These rugged, non contact and low cost encoders come in 4 models: Absolute 9bit - Serial/Parallel; Sine-cosine 3600 and Incremental 128 ppr. The Absolute model comes in 2 variants, A parallel interface and a serial interface (SSI), the parallel, absolute angle information derived by the encoder is converted into serial information by the internal electronics and then transmitted to a receiving electronic circuit in synchronism with a clock. The advantages are a low number of data lines and high reliability. The high resolution is remarkable given the package size of the encoder. The main body of the encoder is 22 mm diameter with an overall height of 19mm and protection up to IP67. The separate magnetic actuator is in stainless steel with bores from 4 to 10mm. These products from Encoder Technology are ideal for hostile environments and with a one off price of around £100 makes good economic sense in a wide variety of applications.