Plano Glide Block
Glide Block :
This block sits in the mounting rail and holds the PLANO clamp in place. It is always attached through the second hole from the top of the clamp.
Note that older PLANO clamps had a solid white nylon block version of this part. The current molded black version is fully interchangeable with this older version.
Now Soldout: to order directly from Sweden www.toolbox.se