PJ1 ULTRA PERFORMANCE FORK TUNER FORK OIL is a High Viscocity Index (H.V.I.) fluid specially blended with anti-foaming additives which provide consistent fork performance superior to standard fok oil, even under servere temperature ranges. Available in 8 different vesocities, from 2.5wt to 30wt and ATF, PJ1 FORK TUNER makes fork tuning easy. Lighter viscocitites are ideal for the quick response needed in motorcross and off-road. Heavier viscocities tune big bike forks for touring conditions and a smoother, firmer ride.