A.0.7~0.8mm B.0.7~0.9cm C.0.9~1.1mm D.0.9~1.1cm
A.0.26~0.52Ω B.0.26~0.52kΩ C.0.52~0.76Ω D.0.52~0.76kΩ
A.有觸點 B.霍爾式 C.光電式 D.電磁式