First, a huge shout out to David at Bike Helmets Direct. This helmet took quite a COVID while to get, but David helpfully kept me updated on progress through the Amazon messaging service. My helmet arrived with a single pad missing (they are all uniquely shaped), and he quickly sent me three pads and a few energy bars for my trouble!I am a big guy, with crewcut hair, with a 60.5cm circumference head (technically, that is a hat size of 7-1/2 but I have always worn a 7-3/4 hat very comfortably). Unlike other Bell helmets, this one isn't offered in an XL size, BUT they claim that the L size in this model goes up to 62 cm. I started my first ride with a simple lightweight skull cap (to wick sweat), and started to have a sore head within 20 minutes. I took it off and rode another 90 minutes without any discomfort. So, 62cm seems like a stretch to me, especillay for someone with longeron the hair, unless my head is oddly shaped (I felt pressure at the back of my head and front quarters).If you have worn a motorcycle helmet or take your car on track days, this helmet will feel weirdly light to you. You will think "This CAN'T be enough protection!" (especially since they are priced pretty similarly!). But, the materials are VERY strong with enough give that you know they will survive an impact at <30 MPH (be honest, do you really expect to hit your head at much more than 20 MPH on a mountain bike?). And, if it does break, imagine what that same impact would have done to your unprotected face?! Still, the price on this is shockingly high, but if you want a REMOVABLE chin guard, this is really the only game in town with this much technology (like MIPS) or style.Although the chin guard does come off, the one-piece design actually wraps all the way around to the back of the helmet where it is split and held together with a latch. Not terribly difficult to get off while you are wearing the helmet but good luck reattaching it while still wearing it! So, while you can probably just pop it loose and wear it around your neck like a clunky necklace to do an extended climb, you will almost certainly have to remove your helmet at the top of the climb to reattach it for the downhill run. Definitely not easy to pop on and off repeatedly for short climbs/descents. It is held VERY securely in place by two front latches near your temples, plus that one in the rear.The helmet comes with two sets of bright yellow cheek pads: MASSIVELY thick and extremely thick. Choose the one that is least UNcomfortable--they will be VERY snug, so there will be NO play at the lower front end of this helmet, which is probably a wise move. There is a rear dial to tighten the "Float Fit DH" system: two oval rings at the back left and right of the helmet that snug it up to the back of your head. They are each about an inch away from the centerline of your head so they grip mostly the back of your head but wrap forward a bit to give you some side-to-side snugness. The cheek pads and the rear loops are really the main contact points for your head.Airflow is very good, and hearing isn't especially impaired. The visor raises just the right amount to allow goggles to be stored completely out of your line of sight if you find yourself in low light. I had NO fogging issues with my goggles (to be fair, mine are Oakley Airbrakes, so they are amazingly fog-resistant on their own). The visor extends about an inch further out than a regular visor, and is angled up a bit more, but the net effect is better sun glare protection without losing vertical field of view on the trail. The visor doesn't come all the way down to where you think it should (even when fully down, there there is a 3/4-inch gap between the rear of the visor and the helmet--they never touch).The "dots" of Velcro that they use to keep the "Xstatic" pads stuck to the inside roof of the helmet are generally pathetic--as I mentioned above, mine came from the factory missing a 2.5-inch long thin pad, almost certainly because it was never really secure. Spare pad sets are nearly impossible to find other than eBay, so make sure you press them all in quite firmly, and check them each time you remove the helmet.This helmet is really excellent. It would be PERFECT if it were $100 less, came with a spare set of Xstatic pads, the visor could be lowered another inch, and had one more set of thinner cheek pads. All of those (except the cost) are trivial complaints--this helmet is a must-have for you if you do serious downhill, especially if you are flying through trees (mine are Redwoods) or frequently bombing through steep rock gardens AND hate climbing while wearing a full-face helmet (like most of us do).