The Kinetic Research Group Arca Rail Short is a short version of the original Arca Rail. It is for mounting onto KRG Spigot Mounts (without an integral Arca Rail) so you can add the Arca Rail to your existing spigot Mount. The KRG Arca rail gives you Arca-Swiss rail functionality for your Non-ARCA Spigot Mount. It's low profile, light weight, and unobtrusive. Attach your bipod to the KRG Arca Clamp or another brand's clamp and quickly remove or re-position for the next stage. Use as many fasteners as possible to mount the rail to maintain rigidity. Fits: KRG Spigot Mounts only