Air & Hydraulic Brake ChamberAir Chamber Type - T20Thrust @ 6.5 bar Air - 8,387 NHydraulic Cylinder Size - Ø30mmThrust @ 100 bar Oi -7,070 NAir & Hydraulic Brake Chambersconvert air pressure into movement ofthe piston/diaphragm which links thetrailer brake leaver to apply the brake;the hydraulic portion allows the use ofhydraulics instead where fitted.