H21B4,SENSOR OPTO SLOT 3MM DARL THRU
H21B5,SENSOR OPTO SLOT 3MM DARL THRU
H21B6,SENSOR OPTO SLOT 3MM DARL THRU
【Apem】H21CG1,
【Apem】H21CG1R2,
H21LOB,SWITCH INTERRUPTER OPEN BUFF-OUT
【Fairchild Semiconductor】H21LOB_Q,光电断续器 INTERUP OPTOLOGIC
H21LOI,SWITCH INTERRUPTER OPEN INV-OUT