Lazer helmets are awesome. I absolutely love the retention system, especially the ability to adjust tightness with one hand while riding if needed. I own a Lazer helmet for road and mtb riding.

My new Lazer Oasiz just arrived from Backcountry. Great service, only few days from order to my door. I adjusted everything, mounted my light and took off for a 2 hr MTB ride.
Setting the helmet up was easy, the Rollsys dial makes getting the right fit a breeze. The Oasiz is lighter & less bulky than my Lazer Ultrax.
I strap my light to my helmets so the shape of the center ribs determines where the light sits and if it will stay tight. The Oasiz is perfect. Parallel center ribs & wide enough to support the light.
At the end of the ride I didn't feel any pressure points or sore spots. The light stayed tight & stable as well.
Overall, I'm very pleased with this helmet and Backcountry.com !

I chose Lazer while searching for a mtb helmet because I liked my Lazer O2 road helmet so much. The O2 with the Rollsys system felt like it was actually custom made for my head and was so comfortable I never felt like I was wearing a helmet. I had very high hopes (and standards) for the Oasiz and it came pretty close. The reason this helmet gets 4/5 stars is because although it's comfortable and I havn't noticed it once through my first few rides, it's got a slighty different shape than the O2 which makes it feel "different" on my head. It also sits much higher on my head. Not bad things, just "different" I guess. The magnetic buckle known as the Magic Buckle is odd at first but very quickly becomes second nature. The sizing is also a bit odd because there is a lot of overlap between a medium and large which can make choosing a size more difficult. I ended up choosing the medium after measuring my head and seeing that I fell into slighty more of the medium range. It's been a very good helmet so far though, I'm pretty much nitpicking to find faults.

This helmet fits awesome. The dial adjuster makes it possible to have a perfect fit. I forget that I even have a helmet on my head it's so comfortable. Absolutely know shaking around on the bumpiest of trails. Sun visor is perfect for blocking mud and sun.