This is a JR NES-507 Standard Servo
Technical Specifications:
Modulation: Analog
Torque: 4.8V: 40.3 oz-in (2.90 kg-cm)
Speed: 4.8V: 0.22 sec/60°
Weight: 1.47 oz (41.7 g)
Dimensions: Length:1.52 in (38.6 mm)
Width: 0.73 in (18.5 mm)
Height: 1.32 in (33.5 mm)
Motor Type: 3-pole
New typical price: $17.95 each Used asking for $12.00 each