2980AC,KNOB 5 ARM 1/4"-20 PHENOLIC
2980AD,KNOB 5 ARM 5/16"-18 PHENOLIC
2980AE,KNOB 5 ARM 3/8"-16 PHENOLIC
2980AK,
2980AL,
2980-B,KNOB 5 ARM 3/8"-16 PLASTIC
2980CG,KNOB 5 ARM THERMOPLASTIC
2980CW,KNOB 5 ARM THERMOPLASTIC