Birfield Snap Ring. This snap ring goes on the outer stub shaft of your birfield and keeps the birfield from drifting too far into the axle assembly.
Specs:

• Warranty: 12 Month Limited Warranty
• Sold As: Each
• Material: Metal
• Finish: Bare
• Color: Grey
• Fits: 1979-1995 Toyota Pickup, 1985-1995 Toyota 4Runner