Bourns PEC12R-4222 (with detents) and PEC12R-4022 (without detents = smooth turning) encoder. LISTING IS FOR CIRCUITBOARD COMPONENT ONLY (Rotary knob is not included) - Option for Notched or un-notched encoder - Has push-button switch in addition to rotation action. - Shaft is 6mm diameter. - D-notched shaft, designed for knobs with tighten