Description Piston ring kit, 3" dia. 3 rings for 184443M91 piston, hydraulic lift. Tractors: TO35 (s/n 179304 & up), MF35, MF50, MF65. For early production tractors: MF135, MF150, MF165 using 3" dia. piston. This item is a suitable alternative for the following: 830741M91, 184447M1, 184447V1, A830741M1, 772984, A-830741M1, 830741M93