Spool,4-1/8" depth, Fits 1-3/4" Round Axle, For Sunflower Disc Models with 8-1/2" spacing. Fits Models 1211, 1212, 1231, 1232, 1233, 1234, 1321, 1331, 1431, 1432, 1433, 1434, 1435, 1441, 1443, 1444, 1541, 1543, 1544, 1550. ReplacesOEM# SN3108