These seem to be fairly standard bumper plate design -- 450mm diameter, with an opening that fits a standard OIympic bar (2inches), though they did seem pretty snug along the bar. The weight on the plates is accurate (10lbs in this case). Theyve also got a skull motif on them, for that "badass look" factor.As other reviewers have mentioned: they do seem rather flexible, perhaps because of how thin they are. I dropped them (on the bar) from waist height several times and they held up well. When I dropped them from chest height they did seem to flex quite a bit (no cracking or damage, though). I didnt try higher than that out of a measure of doubt about whether they could take it or not due to the flexing.That said, I feel I should point out that it seems unlikely that youll be dropping a bar with only 20lbs of weight on it unless youve had some sort of emergency or are being irresponsible. If stacked with other bumper plates the flexibility wouldnt be a concern and Id have full confidence in their durability. Its only alone (and on this 10lbs size) that I have some doubts.These bumper plates seem well made and do in fact have minimal bump on the drop -- which is very important. When dropped these plates barely bounced and didnt go far at all. No going out of control and making a mess or smacking into my shins. They also didnt leave any marks or scuffs on the flooring. Just a clean minimal bump and stop.The plates do seem a bit expensive for the amount of weight youre getting, but thats likely just a part of the premium of the brand, so I wont hold it against them. All in all these seem to be good bumper plates, with my only concern being an issue thats unlikely to actually come up in the course of normal use (why would you need to use bumper plates if youre only adding 20lbs to the bar).So if youre looking for a good bumper plate with a "badass look", here you have it.4/5PS: When you open them, they will stink. A lot. Put them somewhere they can air out for a couple of days and then the smell becomes only noticeable when you are close, much like a tire. Which makes sense, as these use vulcanized rubber.