Designed by world-renowned diamond setter Alexandre Sidorov, the Triple-Edge Clamp is a specialized workholding solution for 21 mm square plates, 20 mm round plates, and pieces that fit between the inside edges, up to 53.25 mm wide. The Alexandre Triple-Edge Clamp mounts directly onto the jaws of GRS® MicroBlocks®. MicroBlock not included. This product is compatible with the GRS MicroBlock® (#003-683, #003-684), MicroBlock® XL (#003-773, #003-774), and MicroBlock® Short Jaw Kit (#003-651). The Alexandre Ring Fixture Adapter (#003-747) allows use with the GRS Standard Block.