Features:Brushless motorReinforced stainless steel final gearHard alumite aluminum gearDual ball bearingsHard servo gear shaftAluminum top caseAluminum heat sink middle caseBlack cableGold plated connectorSerial CompatibleHCS CompatibleSpecifications:Torque: 44.0Kg-cm Speed: 0.08sec/60deg(@8.4V)Torque: 40.0Kg-cm Speed: 0.09sec/60deg(@7.4V)Torque: 33.0Kg-cm Speed: 0.12sec/60deg(@6.0V)Dimensions: 40.4x37.5x20mm (Standard size)Weight: 76.5gOperating voltage: 6.0~7.4V (Lipo, Life, Ni-MH)