This optic plate is made to REPLACE the rear sight of Ruger LC9, LC9s, and LC380 Pistols
Over the different productions, LC9 sometimes changed the tolerance of the dovetail width slightly. It is common after retooling the machine when switching the productions for different parts. The easiest way to solve the problem is to punch a small hole near any edge, to create a small, protruded bump on the insert where it slides into the dovetail.
*** The JPoint, Shield RMSc, Shield SMSc, Shield RMS2, Romeo Zero, Romeo X (SORX1200 only), Vortex Defender CCW, Holosun 507K, Holosun 407K, Sightmark Mini, Riton MPR D2, Riton 3 Tactix MPRD, HEX Wasp, Cyelee CAT PRO, Crimson Trace CTS-1550, and ADE RD3-018 Spike, RD3-021 Nuwa, RD3-021 PRO, RD3-030 Apollo mount using the rear set of mounting holes and do not use the locating pins at the front of the plate. **