Really cool! I was worried it might not mount on my ICS M&P-15 but it did (and easily; it's just a matter of sliding it over the flash hider and using the spring claw to lock it into place. Takes about 5 seconds and it's secure). The sheath is cheap plastic but it's not bad for $10. Goes on a belt and has a clip to pop it off whenever. Mine came bent because of the packaging but I flexed it back ok.
Overall definitely worth the price, but i wouldn't have paid more than $15 or so for it.
Sheath is cool
Goes on my gun well
Makes my gun look like a death machine
Quality isn't anything to brag about
VERY flexible (but it has to be for safety)
Isn't as secure mounted on my M4 as I'd like it to be
Handle is SUPER cheapo plastic
Rating: [4 of 5 Stars!]