Do I need anything (like adaptors, etc.) besides the 2 point sling from ERT to make it work with my PS90? Thanks for patience with a new PS90 user. I ordered Velcro and a brass catcher. So I'm getting ready. Yay! I'm now wondering if I should also get an FN57 pistol just for fun. I carry a Glock model 20 (10mm) or model 29 (10mm) but the 57 should be fun to shoot to plink and at the range.