10mm f.l. diverging lens for Bath Interferometer (mounted)

Description

Focal length 10mm. Good for testing telescope mirrors down to F/4.0 (using cheaper laser with 1.7mm beam I sell) or down to F/2.8 (using glass laser with 2.6mm diameter beam that I sell)

Each lens is cleaned and tested to be sure it is defect free.

Mount for lens is included. Lens will arrive mounted as shown in photo.