The bushing

The bushing may be used in various
applications, but specifically imported for use with an aircraft seat. The
bushing functions as a sliding bearing, as it provides radial support, resists
thrust and allows the seatbelt to rotate. Once installed in the plastic seat
belt shackle, where an attaching bolt is used, the item enables friction to be
considerably reduced and enables the attaching bolt to be tightened without
deforming the plastic shackle. The bushing is constructed of stainless steel
and has an inside diameter that measures .25 inches.

Subheading HS: 8483.30.

Source: https://rulings.cbp.gov/index.asp,  August
14, 2017 (N288428)