Do your front Hydraulic couplers leak while connected to your front implement most times all you need is this simple kit to replace the O-Rings on your Hydraulic couplers. This kit will do 4 Hydraulic couplers.These O-Rings fit the PIONEER 4050 2P hydraulic couplers. This number is stamped on your coupler.This kit will fit the following tractorsJohn Deere 120 140 300 312 314 316 317 318 322 330 332 400 420 and 430 just to name a few.These O-Rings are the correct hydraulic grade VITON, 90 Durometer.