Sig Sauer SRD 9 Pistol suppressor for 9mm handguns Comes with 2 pistons 1/2x28 which is the most common for tilting barrel threaded handguns and another that’s m13.5x This is a NFA class 3 item, there is additional paper work required for this item. The paper work fee is $30 no exceptions. Items require paper work with the ATF to transfer to dealer with an SOT. Time may vary on shipping due to paperwork. Shipping will be applied to any out of state residence. 61A048615