Wing Serov "DS189HV" with “Another style upper case.”
You will be able to use 2style mount.
*Standard mount lug top case included

[Torque] 53.3@6.0v / 59.7@7.4v oz-in 
             3.5 (6.0V)/4.3 (7.4V) kg･cm
[Speed] 0.20 (6.0V)/0.16 (7.4V) Sec/60°
[Dimensions] 1.14x0.43x1.18in / 29 x 11 x 30mm
[Weight] 0.485lb / 0.78oz / 22g
[Wire Length] 50mm
[Voltage Range] 6.0V-8.5V
 
Metal Gear
With Ball Bearing (dual)