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).The helmet is light weight enough for not generating effort in the neck while fresh at the same time, and with a good vision angle.This is my second Bell Super DH as I passed my first one after 2 years onto my youngest son who is just now big enough to wear it. I put 5,000+ miles on the original and it was still in serviceable condition when I bought this new one.For those who are not familiar with this style of convertible helmet, you essentially have two helmets in one. You have a full face and when the chin bar is removed a half shell. Both breath surprisingly well and I have worn both in 90+ degree weather. Obviously without the chin bar it is much more comfortable. This particular version (compared to the Super 3R) is downhill rated which is a series of test that the helmet has to meet to gain this certification. Does it make it better than the Super 3R? Maybe not but the 3R and other convertible helmets that don't have this rating means they couldn't pass the tests ... In any case I got this originally because I was going fast and starting to hit some big jumps (doubles). When you are flying through the air at 15 mph on a 25 foot jump you start to realize how vulnerable you are! My thoughts were, and still are that if you hit your face on a tree, your face is going to lose 100% of the time.This helmet has their version of MIPs which they call spherical MIPS. Essentially the helmet and the inside straps that you head rests into are allows to slip in the event of a crash, reducing the likelihood of trauma. Most high end helmets have some version of this. If you do some reading you'll see it's a feature you should look for in a helmet. Another useful feature is the drip guard on your forehead. It actually does keep sweat from dripping down into your eyes/glasses/goggles. I think most will find the difference size cheek pads to be sufficient to find an appropriate fit.I personally run the chin bar on about 50% of my rides. When I know I'm going to ride something knarly or hit some big jumps I'll bring it. The great thing is you can carry it up on your bars or on your hip pack (as I do with a few bungie type cords) and just put it on when you get ready to drop in. In this way you get the best of both worlds, a breathable half shell on the climbs and full face protections on the descents. I don't think you can put a price on your brain but if you could it would probably be more than $300.My only complaint is the replacement pads are impossible to find now. The next time they are in stock I'm going to buy a bunch as new interior pads make it feel like a new helmet after a few thousand miles!I got it at a great price. Only DH certified helmet that’s convertible. Used it on a downhill day using the full face for over 5 hours and I didn’t even notice it. Used it for regular trail riding using just the top lid and felt safe. The adjustment band is great to tighten it to your head. I recommend itGreat quality, fit is superb and it's light!!! Dont even notice the guard is on other than the comfortable cheek padding. Goggles I ordered fit perfectly with helmet and matched the lime colored accents on brim too. A+ expensive but if youre going to want good protection, awesome quality and comfortable fit, just order the Bell Super DH!He utilizado cascos Bell toda la vida. Y este es la epítome de la perfección. :DReally nice fit!Breathing is very good!Look good without the mouth guardun bon casse mais on s'attend pas a moin au prix tu l'payeWhat an helmet its perfect,light and modulable thanks amazon for your damn hot shipping