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OutdoorMaster Diamond MIPS Ski Helmet – Test and Review

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Updated April 9th, 2024

Outdoormaster diamond mips ski helmet review

The OutdoorMaster Diamond MIPS Ski Helmet is the latest offering from OutdoorMaster. It offers many upgrades from their very popular Kelvin helmet including MIPS. It still comes in at under $100. We got our hands on one to ski with this winter. Keep reading to find out how it performs.

What we liked:

  • MIPS and ASTM2040F-18 certification
  • Goggle anti-fog vents
  • Very comfortable to wear
  • Adjustable vents
  • Polycarbonate In-Mold construction

What we didn’t like:

  • Styling is a little on the bland side
  • No XL or Asian fit sizes are available

OutdoorMaster Diamond MIPS Ski Helmet Review and Test

Ultra XL at Snowbasin scenic
Diamond MIPS with Ultra XL at Snowbasin, Utah
Ultra XL and Diamond MIPS in the trees
Diamond MIPS helmet in the glades at Powder Mountain, Utah

The OutdoorMaster Kelvin is a great helmet for the price retailing at under $40. It is missing several features that most skiers beyond the beginner stage want. This includes MIPS for maximum safety, adjustable venting, and goggle defogging vents. The Diamond includes all these features and more. As a bonus, it comes with a helmet bag.

diamond helmet bag


The Outdoor Master Diamond retails for $99.99 just getting in under the $100 price point. Using our discount code ERO15 you can get it for $85. The helmet is also available on Amazon for the same retail price but without any discount codes.


The Diamond looks a notch more upscale than the Kelvin. It does not have exposed rivets holding on the straps. The helmet uses in-mold construction so the bottom of the shell has a rolled under molding. The Kelvin with ABS shell and glued in liner has a noticeable seam around the edge between the shell and EPS liner.

The Diamond has a PC (polycarbonate) shell with in-mold foam liner. This means that the EPS foam is molded into the shell and not created as a separate mold. This allows for much tighter tolerances in the parts and a better helmet appearance. It has other benefits such as more intricate air vent openings and channels are possible.

diamond construction
Image courtesy of OutdoorMaster

My Diamond MIPS helmet in size large weighed in at 15 ounces. My Anon Echo MIPS helmet weighs 1 lb. The Smith Mission MIPS helmet I reviewed earlier this winter weighed 1 lb 1 ounce. My OutdoorMaster Kelvin helmet weighs 1 lb 1 ounce. The Diamond has a very competitive weight for a MIPS ski and snowboard helmet intended for resort skiing.

OM diamond side view

MIPS – Multi-directional Impact Protection System

MIPS is a layer in your helmet under the energy absorber that allows the helmet exterior shell to rotate relative to your head. This means that for angled impacts such as a glancing blow, the helmet shell will rotate without transferring the rotational force to your head. This reduces the forces going into your head and spine reducing your risk of injury. Learn more about MIPS here.

diamond MIPS diagram
Image courtesy of OutdoorMaster

Safety Certifications

The helmet is certified to ASTM 2040F-18 safety standards. The helmet has a tag inside displaying the cert information.

Removable inner fleece liner

Inside the helmet, you will find the yellow MIPS liner and a removable fleece and mesh lining. The fleece liner feels like a similar material to the Kelvin helmet. It is warm but can get saturated with sweat on warmer days. It is easy to remove for cleaning.

Helmet inside

Audio compatible removable earpads

The earpads snap in and out with plastic tabs. They are completely separate from the interior lining. They have a similar fleece lining on the inside. They have velcro pockets for installing blue tooth speakers. The helmet lining also has a channel for passing the wiring around between the speakers for a neat clean installation.

Check out the Outdoor Master BT01 wireless headphones for a set of speakers that work well with the Diamond MIPS snow helmet.

removeable ear pads

Chin strap

The chin strap has a fleece covering that is smaller profile than what was found on the Kelvin. It’s in line with the padding size you will find on a Smith, Oakley, or Anon helmet. It has plenty of extra length. I wear a size large helmet and with a hat and neck gaiter I still have some extra chin strap to go. I am at the end of the adjustment range on the Kelvin helmet wishing for another inch. I’m really happy to see they made this change.

Adjustable venting

The helmet has 8 vents. The 4 on the top of the helmet are adjustable with a standard slider on top of the helmet. The slider feels smooth and easy to adjust. The OutdoorMaster website claims 11 airflow channels in the helmet. I can count 10 if I count 2 for the goggle/front vent, 1 for each vent on top of the helmet and 1 for each vent on the back of the helmet. I’m not sure where the 11th air channel comes from.

helmet top with vents

Goggle anti fog vents

The 2 front vents work as anti fog vents for your goggles. They work by drawing air through your goggles and passing it around your head. This increases the airflow in your goggles which helps remove fog. This system helps a lot with keeping your goggles clear. They will clear any fog up right away when you start skiing that build up while you were standing around.

diamond vent airflow
Image courtesy of OutdoorMaster

Bungee goggle clip

They got rid of the plastic clip and used a bungee attachment to retain your goggle straps. Smith uses a similar bungee system on their high end Quantum and Vantage helmets. I am worried that the plastic clips used on most low end helmets will break off flexing and exposure to UV rays. Having used a Smith helmet with this feature for years I really like it.

size adjuster and goggle clip


The helmet has a plain dome shape with a small brim in front. Mine is the Meteorite Black version with has a nice black matte finish everywhere. The vents are don’t have any character or shaping to them. The lower shell molding that wraps around the bottom comes in contrasting colors on some models. This helps give the helmet a little more character. I wish the helmet had a few more character lines and shape to give it a little more dynamic appearance. It has similar styling to the Smith Scout/Maze, Oakley Mod 1, Anon Rodan, and Giro Ledge helmets.

Ultra XL and Diamond helmet
Diamond MIPS helmet with Ultra XL goggles
Pulse XL at powder mountain
Diamond MIPS helmet with Pulse XL goggles
Ultra XL at SB
Diamond MIPS with Ultra XL goggles


The Diamond helmet comes in small, medium, and large. The size ranges are as follows.

  • Small 20.1-23.3 inches
  • Mediun 21.7-22.8 inches
  • Large 23.2-24 inches

It has a standard size adjustment dial on the back. Like the Kelvin helmet, the adjuster is easy to use and has a smooth quality feel to it.

The OutdoorMaster Diamond size large has a specified size range of 23.2-24 inches. The OutdoorMaster Kelvin helmet had a size large with a size range from 22-24 inches. I have size Large helmets in both models. When I put them on, the Diamond physically feels larger. The inside of the helmet is wider. I can fit a finger up each side of my head in the Diamond. I cannot in the Kelvin.

The Kelvin ear pads just barely reach the bottom of my earlobes and don’t quite cover the tips. The Diamond ear pads have a solid half inch overlap extending past the bottom of my ear lobes.

The helmet is comfortable to wear. I don’t have any pressure points when wearing it. The earpads feel good with nice pockets to keep them from pressing into my ears. I get headaches with a lot of helmets due to ear pressure. Any helmet that doesn’t so that I can leave the ear pads on is a bonus.

Goggle Compatibility

I have tried this OutdoorMaster ski helmet out with most of the OutdoorMaster goggle lineup including Ultra XL, Vision XL, Pro XM, and the OTG. It works really well with any OutdoorMaster goggles with no goggle gap and a nice fit around the sides.

OutdoorMaster Diamond Snow Helmet with MIPS

diamond mips helmet product image

OutdoorMaster Discount Code

Use the Coupon Code ERO2022 for 10-20% off at OutdoorMaster.com

The Verdict

This OutdoorMaster Diamond MIPS helmet is a nice upgrade from the Kelvin helmet. It has real upgrades such as MIPS, adjustable venting with goggle anti fog vents, and a wider shape that make it well worth the increase in price. I highly recommend anyone looking for a full feature ski helmet to check it out.

Doug Ryan Portrait Skiing 200x200

Ryan Craig
Co-Founder & Chief Editor

I am a total gear nerd and love learning how things work and thinking about how they could be improved. Nothing excites me more than trying out new gear. I’d rather spend 3 hours taking my bike apart and learning how to change something than go to a bike shop. These days, I reside in Michigan by the Great Lakes and go skiing, biking, and boating as much as possible. Visit our About Us page and learn more.


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