The bolt head and locking piece are specific for the PTR32, but some have used different locking pieces from what I've seen. The PTR bolt head uses HK extractor and spring though. I know the rollers and other HK parts should all work on the PTR head if they are not already HK parts. If it's a PTR32 PDW, the recoil rod is not the same as the HK version. It's like the Vectors with a collapsible section. The bolt carrier I believe is the same HK part, as my PTR-32 has a HK bolt carrier, but there is a PTR US part listed as well.