Fits VW Mk4 5 speed manual (bolt in axle flanges):
MK4 GTI/Golf/Jetta/Beetle 2.0L/12V VR6/TDI/1.8/1.8T/V5
MK3 Jetta TDI 5-speed
The 180WK 02J will fit until 2004 (114mm ring gear inner diameter)
The 181WK 02JB's after 2004 will have a 113mm ring gear inner diameter

Install kit sold seperately HERE

Wavetrac diffs are state-of-the-art helical gear differentials designed, developed, and manufactured in the USA by Autotech Driveline. The VW 5-Speed Wavetrac Differential is the only torque biasing Volkswagen differential on the market with patented technology that mitigates wheelspin when an unloaded wheel condition arises. During zero axle load conditions, the Wavetrac cam device acts to create internal load, maintaining drive on the gripping wheel instead of acting like an open diff (and going nowhere!). Super strong 9310 alloy steel gears are enclosed in case-hardened steel bodies, held together with ARP fasteners. All Wavetrac differentials include a transferable, Limited Lifetime Warranty.