Micro Servo with 3-pin JST Cable - Adafruit

3x AA Battery Holder with On/Off Switch and 2-Pin JST

This high-torque standard servo now comes in a metal-gear flavor, for extra-high torque (10 kg*cm!) and reliability! It can rotate at least 120

Standard Size - High Torque - Metal Gear Servo

Micro Servo with Alligator Clips : ID 5592 : $7.95 : Adafruit

Add more power to your robot with this metal-geared MG90D servo. The tiny little servo can rotate approximately 90 degrees (45 in each direction) and

Micro Servo - MG90D High Torque Metal Gear

Grove - Cable Pigtail - 4-pin connection cable - 10cm - Adafruit

Servo Extension Cable - 30cm / 12 long - : ID 972 : $1.95

Adafruit LC709203F LiPoly / LiIon Fuel Gauge and Battery Monitor

The Adafruit 16-Channel 12-bit PWM/Servo HAT will drive up to 16 servos or PWM outputs over I2C with only 2 pins. The on-board PWM controller will drive all 16 channels simultaneously with no additional Raspberry Pi processing overhead. What's more, you can stack up to 62 of them to control up to 992 servos - all with the same 2 pins! It can also do PWM up to 1.6 KHz with 12 bit precision, all completely free-running.

Adafruit 16-Channel PWM / Servo Hat for Raspberry Pi - Mini Kit [ADA2327]

Analog Feedback Micro Servo - Metal Gear ADA1450