The two set screws on the Hex side have been left loose as this is an accessory/adapter.

Side A: 5 mm Diameter Shaft (With Set Screws)

Side B: 0.156 Hexagon or 1/4" Shaft (With Set Screws)

Coupler Diameter: 0.499"

Coupler Length: 0.911"

LOCATION: CAB1B - 100104 REF D1538