YOA56X Brand: Hobbywing. Model: Pentium-18A. Continuous current: 18A. Burst current: 22A up to 10 seconds. Input Voltage:  2-4 cells lithium battery or 5-12 cells NiCd/NIMH battery.    BEC: 2A / 5V (linear mode). Max Speed: 210，000rpm for 2 Poles BLM， 70，000rpm for 6 poles BLM， 35，000rpm for 12 poles BLM (BLM: Brushless Motor). Size: 45mm (L) * 24mm (W) * 11mm (H). Weight: 19g.  Package Details Weight: 20.33 g Size: 45*24*11 cm Package Includes 1 × Brushless Motor ESC Speed Controller