Trailer bearing oiler tool 2.717

Feature:
Fitment:This trailer bearing buddy measures 2.717 at its base. It is designed to be used in most 8 bolt hubs.
Safe and Secure:If your trailer is often in a saltwater environment or needs to be driven on the highway for a longer period of time, then this trailer partner bearing protector is vital for the bearings; replacing them is always a hassle and having them allows you to drive with peace of mind that the expiration date can be long.
Excellent Material:Made of high quality stainless steel with maximum anti-corrosion ability. There is also a matching rubber trailer hub caps.
How to work:The axle hub is filled with grease until the grease forces the piston outward about 1/8 inch. Because the piston is spring loaded, the piston exerts a slight (3 psi) pressure against the grease, which maintains a slight pressure between the inside of the hub and the outside environment. When the hub is submerged, water cannot enter the hub because of this pressure.
An automatic pressure relief feature prevents over-filling and over pressurization. Without this feature, the inner seal will be damaged. Grease can be added to the hub through an easily accessible grease fitting located in the center of the piston. Lubricant level (and pressure) can be checked quickly by pressing on the edge of the moveable piston.If you can rock or move the piston, the hub is properly filled. These bearing buddy’s will last the life of your trailer.
Easy Installation:Installation is very easy, no need to use complicated tools.
What you get: 4pcs Boat Trailer Bearing Buddy