From Kingmax this super thin 6mm digital wing servo has impressive performance:

Gear：Full metal
Spline：Exclusive
Motor：Coreless motor
Bearing：2BB
Dead band：2μs default
Waterproof：No
Operating Voltage：DC3.5~7.4V
Rated working voltage：DC 7.4V
Working frequence：1520μs/330hz
Working angle：±63°@800us-2200us
Working temperature：-10℃~+50℃
Storage temperature：-20℃~+60℃

Features:

• High performance, digital multivoltage micro wing servo
• High-precision metal gears
• Full CNC aluminium Casing
• High quality coreless motor
• 6mm ultra-thin thickness
• Dual ball bearings

Specifications:

• Operating Speed(3.5V):0.23sec/60degrees
• Operating Speed(5.0V):0.15sec/60degrees
• Operating Speed(6.0V):0.13sec/60degrees
• Operating Speed(7.4V):0.10sec/60degrees
• Stall torque(7.4V):4.2kg.cm(58.33oz/in)
• Rated working torque(3.5V):1.0kg.cm(13.89oz/in)
• Rated working torque(5.0V):1.6kg.cm(22.22oz/in)
• Rated working torque(6.0V):2.0kg.cm(27.78oz/in)
• Rated working torque(7.4V):2.7kg.cm(37.50oz/in)
• Dimensions:23x6x25.2mm /0.89X0.23X0.97in
• Weight:9g(0.31oz)
• Connector Wire Length:JR180mm(7.02in)