Forged high quality alloy steel cross is case hardened to provide good wear resistance and maximum service life; Pre-installed grease fitting in the cross saves time, prevents installation damage and allows for easy U-Joint maintenance Seals are made out of high quality nitrile rubber for optimal grease retention and contaminant exclusion; Multi-lip seal is pliable, yet tough and tear resistant Forged high strength steel cups are case hardened for strength and durability; Cup face and outer diameter are precision ground to provide precise fit, lock up and balance ability All U-Joints are pre-lubricated with a premium, high temperature grease that performs well in a wide temperature range and provides a long service life