Gib, X1 Micro Mill X-Axis, 120 mm 

Specifications

Length	4.7" (120 mm)
Width	0.4" (9 mm)
Thickness	0.1" (3 mm)

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

Item No	Models
10	LittleMachineShop.com 4660 HiTorque Micro Mill LittleMachineShop.com 4700 HiTorque Micro Mill
115	Harbor Freight 47158 Central Machinery Micro Mill Clarke CMD10 Metalworker Micro Mill Various X1-US SIEG Micro Mill

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