This Tandem Axle Trailer Equalizer Bar is used with Double Eye Leaf Springs on your Dual Axle Trailer to equalize the load between the two axles. If your trailer has an Equalizer bar already, then its important to replace it with the same size equalizer bar in order to keep all of the suspension components in the correct locations with regards to the Trailer Fenders and axle clearances. This is the EQ 104 size Equalizer bar (sometimes referred to as a rocker bar). If your Equalizer Bar is rusted and you cannot see the EQ Number on the center of it, you can verify whether or not its a match by taking a few quick measurements. The Width between the mounting hole bushing measures 5 3/4" on this equalizer bar, and the Height (From the center of the top hole to the center line between the other 2 holes) measures 2".The EQ 104 Equalizer bar is black painted to help resist corrosion, and to match the Trailer Frame of many Utility and Freshwater Boat Trailers. The Nylon Bushings that are included within the mounting holes of this EQ Stabilizer bar are 9/16" in diameter, which most trailer suspension hardware will fit. If you need a different sized bushing, we have them for sale here on our website.Features:- EQ 104- 5 3/4" x 2" Center To Center Measurements- Black Painted- 9/16" diameter bushing included