Features: 1.Premium stainless steel material, firm, corrosion resistant and durable to use. 2.The automatic check function indicates the level of grease to prevent grease failure. Most tailor?made hub bearings have a 2.441?inch hub diameter. 3.Extend service life, keep dirt and water out of your hubs and bearings. 4.Easy to install, no complicated tools required, convenient for using. 5.Bearing buddys put a small amount internal pressure in the hub (about 3psi). When the hub is submerged water cannot enter the hub because of this pressure. Specification: Condition: Brand New_x000D_ Item Type: Trailer Bearing Buddy_x000D_ Material: Stainless Steel_x000D_ Color: As picture shown_x000D_ Bearing Buddy Bottom Size: Approx. 2.441in_x000D_ Application: Designed to be used in most 6 boltshubs. _x000D_ Product Tolerance: -0.02 to -0.05mm_x000D_ Instruction:_x000D_ Bearing buddys put a small amount internal pressure in the hub (about 3psi). When the hub is submerged water cannot enter the hub because of this pressure. Its a great way to extend bearing life and service your bearings in-between hub re-packs. Bearing Buddy's help keep dirt and water out of your hubs and bearings. The blue indicator ring will protrude out to let you know when your bearing buddy is full, or sink back in to let you know that you need to add grease.