PARFOCAL TUBE FOR Spencer, AO American Optical TRINOCULAR MICROSCOPE

Description

This solid aluminum coupler/phototube attaches to Spencer 10 series, American Optical 110 and 120 series  trinocular heads and AO Microstar series trinocular heads on one end and provides an opening on the other end for a standard 23mm eyepiece mount. This unit is designed to be parfocal (in focus when changing from binocular viewing to trinocular viewing).
The smaller images are of the same phototube from a different angle. This auction includes one phototube only.
I accept Paypal as payment. Buyer pays .00 shipping/handling. (US Only)