FKB1406 SERIES SPECIFICATIONS Specification Item Mechanical Number of Keys (US) Key Switch Type Membrane switch Keytop style Rectangular cylindrical 60 gf ±20 gf (2.112±0.704 oz.) Operating Force 1.5 mm ±0.3 mm (0.059 in. ±0.011 in.) Stroke Tactile 20 gf typ. (0.704 oz.), soft type Operating Life 5 M operations min.