Micro Switch 

In your instruction manual, this part appears on the parts list as:

Item No	Models
167	Grizzly G0619 Grizzly Small Mill Various SX3 SIEG Small Mill
191	LittleMachineShop.com 3536 HiTorque Bench Lathe - 8.5x16 LittleMachineShop.com 3540 HiTorque Bench Lathe - 8.5x20 LittleMachineShop.com 3595 HiTorque Bench Lathe - 8.5x20 Various SC4-US SIEG Bench Lathe Travers Tools OT218410 OTMT Bench Lathe - 8.5x16
267	BusyBee CX611 Craftex Small Mill Various SX3 SIEG Small Mill

Click your model to see the complete parts list.