My Atmos helmet had cracked on the back from a fall, so I needed a replacement. I got the same size as the Atmos in this model because I figured it was the sam brand so should be the same size. Although the inside of the helmet is the same size and the retention mechanism fits me even better on this one compared to the Atmos, the entire shell is considerably bigger in the Ionos. It is also about 50 grams heavier. The color selection in this and the Atmos did not have any that I can say I liked, but this was the closest to that description. I guess the true test of a helmet is the lack of head injury during a fall, so this would have to be a preliminary test for now. The sale price at Competitive Cyclist could not be beaten or come even close by anyone else despite discounts, sales, and coupons combined.



Finally broke down and bought this to mount it on my helmet. I was using another mount in my Atmos, but it was not optimal as the camera would sit on the side of the helmet. The weight would make the helmet tilt to the left some over time making the picture/video crooked. This sits easily on the top of the helmet and it is so much easier to adjust the camera. Have not done any videos with it yet, but mounting it was as easy as it gets.