The SG90 servo is probably one of the most versatile servomotors and is widely used in all kinds of robotics projects. It's very small but still offers a respectable force of 1.8 kg/cm, making it suitable for moving various mechanical parts like for instance a dome cover of an all sky camera.

Specifications:

• Weight: 9 grams
• Dimensions: 22.2 x 11.8 x 31 mm
• Torque: 1.8 kg/cm
• Speed: 0.1 s/60 degrees
• Power supply: 4.8 V (~5V)
• Operating temperature: 0 ºC – 55 ºC