No more cracked or broken stock aluminum axle housings with this unit. The "Anvil" is a CALMINI exclusive, and is completely fabricated from scratch as a replacement housing designed to handle any kind of off-road abuse. Uses the steel third member housings from a Vitara/Grand Vitara. We've even built in additional strength by including a replacement passenger (short) side axle that rides on an outside bearing built into the housing. The slick part is that it now uses a drivers (left) side outer axle on both sides! You now only have to carry one spare! Kit comes complete with CALMINI built Anvil housing, billet machined stub axle, seals, bearing, c-clips, oil drain plugs, polyurethane bushings, complete hardware, and installation instructions. If you're into hard core off-road use of your Sidekick/Tracker and your rig has our 3" suspension system, you NEED this setup!