These clamping blocks used to be available from an American company but are no longer listed so I made some of my own!!
Allows you to provide clamping pressure across a variety of joints to give a perfect glue seam 

Use the Circle end for clamping irregular angles or the triangle end for standard 90-degree mitres.

Made from high quality PETG durable plastic, much more durable and stronger than normal 3D printing plastic, see video showing me clamping a bessey clamp as hard as I can with no deformation/damage to mitre block!!

Size: 30x15x160mm (1 1/8" x 9/16" x 6 5/16")

4 blocks included (bessey clamps not included!!)