I am building a vacuum system for a lathe and I need a spindle that will spin at up to 3000 RPM and a heavy duty vacuum hose. I was looking for a roller bearing with rubber seals on both sides (hence -2RS). This camp is perfect. Smooth rotation, dimensional accuracy, noiselessness. I turned the threads on the 1/4" NPT burr hose adapter and epoxyed it to the inner race.