The RGR rotary ring encoders provide speeds in excess of 2000 rpm with resolutions down to 0.2 mm arc seconds. Using the company's RG2 readheads with 10 mm x 10 mm stainless steel rings, the devices are available in 3'', 4'', 6'' and 8'' diameters and can be used on both solid and hollow shafts. The rings come with a pre-counted number of lines and offer repeatable reference marks as an option. Digital or analog incremental outputs are also available.