Check the listing for details. Brotherhobby EngineerX 2307 2500kv Motor. Color: Blue, Condition: New. Listed at 23.99 USD. In collaboration with EngineerX, Brotherhobby has released a new lineup of 2307 motors tailored towards freestyle. They come in three options of KV, 1750kv for the 5-6s freaks, and 2500kv-2700kv for others.One of the first thing you notice looking at the motor is that is doesn't look like a standard motor! The round shape sets this motor apart and the ridges on the bell give more surface area to help cooling when spooled up. Brotherhobby decided to keep a closed base and this makes sense on a freestyle motor to help strengthen the motor and protect the windings and stators from damage during all those long sessions.The shaft is fully hollow and the top of the bell has a texture to prevent propeller slip. The motor leads are long (150mm) to fit on larger frames such as 6". SpecificationsKV: 2500KVConfiguration: 12N14PNo.of Cells(Lipo): 4-5SMagnet: Black N52H arc magnetsWire AWG: 20AWGShaft: Titanium Alloy hollow shaftStator: 0.15mm Nippon Steel silicon steelBearings: Japan NMB 9x 4 x 4mmBase casing: Al 7075Bell cap: Al 7075Weight: 36g