FITS YOUR FULL SIZE HK OR COMPACT HK RAIL TO GIVE A PICATINNY UNIVERSAL RAIL TO MOUNT UNIVERSAL LASERS AND FLASHLIGHTS Availability: Usually ships the same business day. HK PISTOL ADAPTER MUSP MCUSPMSRP: $24.99USA Optics: $17.00FULL: SIZECOMPACT Have a Question? Interested in an item? Give us a call or Send us an E-mail! Phone:1-404-433-7371 E-Mail: LauraAMeade@aol.com or mbskin@yahoo.com We're available anytime after 8:30amEST!!