The 3/16” Mounting Spacer for the Retriever Pro Models measures 2" x 2.25". It fits perfectly under the base mount of the Quiver/Clamp Assembly and is used when the Retriever needs to be pushed away from the bow riser. One spacer is included in the "hardware packet" shipped with every AMS Retriever Pro. We also carry a longer spacer (Z111) used for mounting our sight.