The Xing-E Pro series is an economical alternative to the excellent iFlight Xing motors, suitable for both freestyle and racing flying with a very good price/performance ratio. They are durable, powerful, and affordable. This motor features a solid 4mm hollow steel shaft, larger NSK 9x4x4mm bearings, and high-quality bent N52SH magnets. The pro version is in unibell design. We recommend the 2450Kv version for standard 5" quadcopters in combination with a 4S battery.