Absolute hollow-shaft rotary encoder
GURLEY Precision Instruments

The Hollow-Shaft Optical Encoders are rugged, high-performance devices designed for use where precise motion sensing is critical.
The Series 835H is available in three different models. They have the same mechanical and electrical features, but differ in performance and price.

The following features are common to all models:
Optional zero index Fits any size shaft up to 1.2"(30mm) diameter Simpler design of user's shaft: No threads, shoulders, or critical length requirements Internal flexible coupling for easier installation Combination synchro/face mount or square-flange mount Shielded ABEC Class 7 bearings for protection against contaminants Precise chrome-on-glass disc.