Shaft, Head Support, Air Spring, HiTorque Mini Mill 

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

Item No	Models
120	LittleMachineShop.com 6450 HiTorque Mini Mill
156	LittleMachineShop.com 4962 SIEG Mini Mill (X2D)
161	LittleMachineShop.com 4190 HiTorque Mini Mill
168	LittleMachineShop.com 3990 HiTorque Mini Mill

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