Spektrum Firma 85A Brushless Smart ESC / 3300Kv Sensorless Motor Combo, Black. Spektrum Firma 85A Brushless Smart Esc / 3300Kv Sensorless Motor Combo, Spmxsemc01. Package Height: 6.36 Inches. Item Package Weight: 0.44 Pounds. Spektrum Firma 85A Brushless Smart ESC / 3300Kv Sensorless Motor Combo, SPMXSEMC01.