Pair of Round Hole 400mm Aluminum and Solid Steel Air Shock Absorber Pressure can be adjusted by springs or air (nitrogen); Operation of the coil-over springs and air cylinder is helpful to reduce the shock. Shock Absorber bottom/ends type: Round End No instruction included, professional installation recommended. Universal fit for most 400mm Motorcycle Shock Absorber For Honda/Yamaha/Suzuki/;Dirt bikes, Gokart, ATV, Motorcycles and Quad; (Please be noted, if your vehicle is too heavy, especially for ATV, please kindly check the Maximum load of the shocks before placing order. ) Description: Dimension: Total Length: 430mm (17″) Length of Eye to Eye Core: 400mm (15 3/4″) Eye Diameter(with bushing): 12mm Eye Diameter(with bushing removed): 16mm Eye Thickness: 21mm Eye Maximum Tensile Strength: 2,000 Kgf Spring Thickness: 8mm Spring Width: 60mm Working Stroke: 68mm Spring Stiffness: 110 kg Maximum load: 300 kg (660 lbs) Air Reservoir: Adjustable Factory Air Pressure: 0.4