Designed to handle the demands of high mileage and severe use class 3-6 trucks and buses Shouldered bushing and bonded bushing with sleeve protects from bushing walkout for improved quality arc welds up to 360° for durability Robust hydraulic lock out prevents over extension of air bags top out of the piston and averts damage to seal assembly on most applications All weather fluid contains special additives to assist with extreme temperatures and help reduce oil breakdown while 2 in. or 2-1/4 in. reserve tube holds more fluid to improve performance when required 10 Stage valving tuned specifically to each vehicle adjusts to road extremes while larger 1-3/8 in. bore provides more efficient damping control to provide consistency and a smooth ride most applications