This is the Futaba BLS172SV S.Bus2 UHT High Voltage Programmable Metal Gear Servo.

Features:

• Ultra high torque
• Programmable and compatible with S.Bus and S.Bus2
• Aluminum center case
• Brushless motor offers incredible holding power and 5X longer life than servos equipped with brushed motors
• Handles up to 2S LiPo power
• Dual ball bearing supported output shaft
• One year limited warranty through Hobby Services beginning at date of purchase

Includes:
One Futaba BLS172SV S.Bus2 UHT High Voltage Programmable Metal Gear Servo with Instructions, 0.83 (21mm) Round Horn, 1.8” (45mm) Round Horn, 1.5” (39mm) Four Point Horn, 1.2” (32mm) Six Point Horn, and Four each Grommets, Eyelets and Mounting Screws

Torque: 514 oz-in (37 kg-cm) @ 7.4V
Speed: 0.11 sec/60? @ 7.4V
Dimensions: 1-9/16 x 13/16 x 1-1/2" (41 x 21 x 38mm)
Weight: 2.6 oz (74 g)