Cheerwing 4x 4pcs Emax ES08MDII 12g/ 2.4kg/ .08sec High-speed Mini Metal Gear Digital Servo ES08MD -US Model: ES08MD Size: 23 x 11.5 x 24 mm(9.05 x 4.5 x 9.44 in) Weight: 13g / 0.42oz Operating voltage: 4.8V~6.0V Operating speed (no load): 0.12sec/60 @ 4.8V; 0.10sec/60 @ 6V