Hobbywing xerun axe r2 sensored brushless crawler esc features stronger performance thanks to foc technology (field-oriented control) extremely sensitive control of the speed professional handbrake function to have a firm footing even on steep slopes dual running mode: forward / backward (rock crawler) and forward / backward with brake (normal) built-in bluetooth module water resistant multiple controller protection functions including reverse polarity protection programming via app ""hw link"" compatible only with xerun axe ""r2"" motor series specifications type: brushless foc max cont/peak current: 80a/480a cells count: 2s-3s lipo, 6-9 zellen nimh motor limit: for xerun-axe ""r2"" range bec: 6v/7. 4v with 6a programming: via bluetooth & app ""hw link"" waterproof: yes dimensions: 47,4 x 36,2 x 26,5mm weight: 108g usage: 1/10 rock crawler (hw30112102)