Avtron M4 hollow shaft encoder, 5/8" to 1 1/8" [16-25mm] has been replaced with the HS45 upgraded model, which offers larger bearings and potted construction for increased durability, as well as LED and remote diagnostics. HS45 replaces these models with no rewiring and no mechanical changes.
Looking for M4-1 or M4-2 solid shaft models? These were replaced by the upgraded AV485 encoder, offering severe duty construction with larger bearings and potted electronics as well.
Looking for M4 large-bore models > 1 1/8"/48mm shaft size? They are a current model, click here for the M4-Large-Bore encoder.