Home > Products > Incremental Encoders > Light Duty > HTR-OS HTR-OS Click on the Photo to enlarge Specifications Features Diameter 32 mm. Shaft 4 mm. Pulse per Revolution: 40~500 PPR. NPN Voltage / NPN Open Collector Small and Economical Encoder Detailed product specifications by the below attachment, please open the PDF file Date Sheet Related products HTR-5B HTR-M2 HTR-OS HTR-W HTR-3A