61C11-01-08-01 - 

Grayhill 61C Series Optical Encoders
The 61C series encoders offer either 16 or 32 positions and have a built in pushbutton. They are designed for operational use to move display icons and select the highlighted option. They are extremely cost effective and as they are optically coupled they have an operational expectancy of more than a million rotations helping to reduce maintenance. They are also CMOS, TTL and HCMOS Logic compatible.