for switches item no.: 506 U, 507 U, 502 U, 503 U, 506-20 U, 507-20 U
for pushbutton switches item no.: 506 TU, 507 TU, 502 TU
for buttons item no.: 531 U, 532 U, 533 U, 533-2 U
for multi-switch item no.: 531-41 U