–  Designation Code Description  1.Diameter  N2 D2  Φ 22mm, Φ 25mm N3 D3  Φ 30mm  2.Type IF Flat Head IL Protrude Head IM Mushroom Head 37 IK Latch Mushroom Head IA Momentary Protrude IB Momentary Mushroom 37 ITL Double Push Button