REAR SHOCK ABSORBERS BITUBO HD033WME03 HARLEY DAVIDSON FXDB DYNA STREET BOB 2012 > 2017. The linear or progressive springs are chosen according to the type of vehicle application. The wide adjustments range offers excellent performance, for the rider only or at full load. He shocks are pressurized with Nitrogen gas with oil/gas separate floating piston. Shock body in high resistance alloy steel. Billet aluminium heads with CNC machining.