The R-series by Novotechnik use a magnetic pick-up to determine angle so there is mechanical wear on the product.

Novotechnik U.S. introduces the R-Series of magnetic rotary angle sensors. These sensors use the orientation of a magnetic pick up to determine angle so that there is no mechanical wear.
An embedded microprocessor, contained within the R-Series sensors, converts the magnetic orientation to an analog output that is repeatable to within 0.03% or 0.1° of measurement range depending on model. These rotary position sensors can be programmed and reprogrammed for the application’s angle, CW/CCW direction and single or redundant output can be selected.
R-Series have a measurement range up to 360° and have 12- or 14-bit resolution, depending on model. R-Series models include RSC28, RFC48, RSC66 and RFA4000 sensors.
Novotechnik U.S., Inc.
– Edited by Chris Vavra, Control Engineering, www.controleng.com
https://www.controleng.com/sensors