2.125" ID x 3.376" OD Trailer Hub Grease Every spring and fall we drive 5,500 miles from Lower Alabama to Montana and back (taking detours through some of our favorite scenery). I remove hubs before every ride, check bearings, lube and replace seals I have used three sets of these seals so far and have had no complaints. It's a spring seat double seal that seems to work well. I always put some wheel grease on the rubber part of the seal. This will keep the dry rubber from touching the metal when the wheel starts to roll. I've been doing this for 49 years and zero mistakes. It's a good deal for the money. I would recommend these fillings. Just make sure YOU order the right size! Much luck!