This is an optional accessory of a laser autocollimator.
LAC-PLM is the parallelism of the two-sided plane mirror is an exact parallel.
You can use criteria such as out of the surface does not reflect.
In the measurement of common grazing, small plane mirror will also be used if desired.

※LAC-PLM is Nikon Instech Co., Ltd. will be the distributor.
Please contact Nikon Co., Ltd. for the RoHS Directive.