1、Just choose the perfect size and model for your wheel cover, and it will fit your bearing well and won't fall off for miles. 2、These bearing partners will help you avoid serious mechanical problems; provide long‑lasting and economical solutions for your bearing protection. 3、The bearing partner maintains pressure on the grease in the bearing to prevent water and dust from entering. 4、The spring‑loaded piston exerts a slight pressure of 3 psi on the grease, thereby maintaining a slight pressure between the inside of the hub and the outside environment. 5、The automatic pressure relief function can prevent over filling and over pressurization, which can meet your needs well. 6、Easy and simple to install on your bearings, filling them with a grease gun is very simple and quick, and will not cause confusion. 7、Just remove the cover and you can monitor the grease level at any time to provide special protection for your bearings.