The LASER PRO® LCL-R Rechargeable Green Laser Sight & LED Light for Ruger compact to full-size pistols and hand guns with a rail, including but not limited to:  Ruger SR9 SR40 American Security-9 Security-380 & [Mark IV Tactical w/rail under barrel]

This laser fits weaver-style and picatinny rails that have cross notches. A distance of 1 3/8 inches between the cross notch in the rail to the front of the trigger guard is needed for this laser to fit. LASERPRO lasers are a Class IIIR laser with a peak power output less than 5mW. Adjustable for windage and elevation. AC Adapt