Specifications:

These metal upgrade parts are compatible with sj series gel ball blasters like sj mk18,  sj m4, or  sj hk416d etc,.
Brand: si jun.
Material: metal.
Color black.

Package includes:

1x metal charging handle.
or 1x metal blowback kit.
or 1x metal dust cover.
or 1x metal mag release.
or 1x metal dowel.