Spektrum Smart Firma 130A Brushless Esc with 3150KV Motor Rc Part #9504 July 1, 2023 admin Spektrum Smart Firma 130A Brushless Esc w/ 3150KV Motor Rc Part #9504. Condition is “Used”, this combo works great and appears to have no issues. Motor has 5 mm shaft and combo has little use. Please view other rc items.