Retaining Ring. Fits: Most Oliver 1550, 1555, 1650, 1655, 1750, 1755, 1800, 1850, 1855, 1900, 1950, 1950-T, 1955. White 2-70, 2-85, 2-88, 2-105, 2-110. #70929388. Replaces K2031B, 30-3223701, 72160671.