MKS have released the new HV6120H servo specifically for use in those smaller applications requiring an even thinner servo and at 8mm  it makes it ideal for F3K. F5J and those super slim wing sports models that are now the rage.

Full metal casing with metal gearing and High Voltage for speed and torque makes the HV6120H durable, precise and reliable use as what is come to be expected of MKS

Specifications:

Torque (3.7V):  2.54 kg-cm / 35.2 oz-in
Torque (4.8V):  3.3 kg-cm / 45.8 oz-in
Torque (6.0V):  4.1 kg-cm / 56.9 oz-in
Torque (7.4V):  5.0 kg-cm / 69.4 oz-in
Torque (8.2V):  5.4 kg-cm / 74.9 oz-in
Speed:    0.180s (3.7V)  / 0.139s (4.8V)  /   0.110s (6.0V)  / 0.089s (7.4V)  /  0.080s (8.2V)
 Weight:  11 g  /  0.388 oz
Dimension:  23 x 8 x 25.2 mm