I think it is a SERPA: Is there something wrong with them? Prematurely wear? gouge pistol finish? The only problem I have with mine is that one spot on my Beretta's slide seems to bear the brunt of scuffing, but a bit of oil/grease/vaseline minimizes that.
Potential safety issues and the lock mech can lock up forceing you to cut the holster off the gun. Just google it there is tons of info out there. Many shooting schools ban them. Short answer is generally unsafe.
Save your self the issue and just spend the extra 15 or 20 and get a good holster.
You can PM me if you want, I dont want to derail the thread further.
Shawn