Firma 3900Kv 4-pole Brushless Motor

Overview
Great choice for 1/10 Scale 4WD models looking for a high RPM motor upgrade running up to 3S * (12.6v) power. Low cog 4-pole rotor design, CNC machined aluminum housing, insulated high purity copper windings, high-quality alloy steel 5mm output shaft, and high-precision bearings for high durability and smooth rotation. Preinstalled with 4mm gold plated bullet connectors for easy installation. Perfectly matched for the Firma 130 Smart ESC.
*Will work with the 85A Firma ESC, but only for 2S power.
Features
Perfect upgrade for brushed 540- and 550-size brushed motors with the same diameter and mounting pattern (vehicle must accept pinions with a 5mm bore)
High-quality 4-pole sintered rotors
Includes 4mm gold plated bullet connectors
Precision ball bearings and hardened steel 5mm shaft
SafeD-5 Pinion compatible