Staccato HDP4. Has about 2K rounds thru it. Never had a single issue. Gun shoots amazing and flat. Only selling because I have the C4X now. Ported by monsoon tactical. Re DLC coated by staccato. Will sell with SRO, FDE Acro P2 or no optic. With Acro $4200. Sro $4000. No optic $3600. No trades. Will meet at local FFL for PPT. No shipping. Thanks