ARRIS Swift Series BLHeli 20A 2-4S BEC 5V/1A Brushless ESC for RC Multi-Rotor (2PCS) BLheli firmware, support Oneshot 125. Continuous Current: 20A; Burst Current (10S): 30A BEC: 5V/1A; Lipo Cells: 2-4S The firmware is specialized for multi-rotor, fast throtthle response during flying. 8 Timing setting , makes motors work with the best condition. Copy this link to broswer to download the manual: http://site.hobby-wing.com/manual/ARRIS-Swift-ESC-Manual.pdf