For all your optical bench mounting needs, we have a wide selection of base and angle plates. The 9918 has two perpendicular slots while the 9915 has a pair of in-line slots. Also available are the 9912 and 9914 with long slots on either side and a larger baseplate with multiple mounting holes and an extra slot on either side. Two angle plates are also provided for orthogonal mounting. The 9101 has surfaces and edges which are machined with parallelism and perpendicularity to within 0.003". The slots are 1" or, in the metric version, 25.0 mm apart. For easy mounting to the angle plate, there are 1/4-20 (M6) and 8-32 (M4) threaded and through holes. The small 9102 angle plate is ideal for making quick setups on an optical table. The black-anodized aluminum plate has a convenient array of 8-32 and M4 threaded holes and a 1/4-20 (M6) through hole for use with conventional mounts. There are also four 2-56 threaded holes for use with our Tiny mirror mounts.