18-Tooth Sprocket.  Ball Bearing.

Used on:

Allis Chalmers CA, D-14, D-17.

Case 400, 800.

Farmall Large M, 400, 450, 560.

Ford 900, 901.

John Deere 60, 620, 730, 10.

Massey Harris Large 44.

Oliver Super 88, 880, Checkerboard.