This is the GY240 Gyro with SMM Technology from Futaba. This is a High Performance, Compact and Lightweight (AVCS) Angular Vector Control System gyro developed for model helicopters. Because the sensor and control circuit are integrated, it is simple to install. One Year Warranty FEATURES: AVCS System: (Heading Hold) Since the rudder trim changes (caused by wind and other meteorological changes); the front, rear, and other heli attitudes change and are automatically cancelled; tail (rudder) operation is easy, making it perfect for 3D Flight. SMM Gyro Sensor: Use of this newly developed technology virtually eliminates rudder trim changes during flight (see COMMENTS). Integrated, compact and lightweight design made possible by high density mounting technology. Conductive Resin Case: This case improves EMC (Electrostatic and electromagnetic interference) resistance. INCLUDES: One GY240 gyro One mini plastic adjustment screwdriver Three mounting pads One instruction sheet SPECS: GY240 Gyro- Length: 1-1/16" (27mm) Width: 1-1/16" (27mm) Height: ¾" (19mm) Weight: 0.88oz (25g) Voltage- use only with a 4.8V battery. (if you use it with a higher voltage battery it needs to be regulated to 6V) COMMENTS: Can be used in helicopters and airplanes (Due to 0-100% Gain Adjust). The new SMM (Silicon Micro Machine) technology is the integration of mechanical elements, sensors, actuators and electronics all brought together on a common substrate chip. This hobby industry first, results in a gyro sensor with an unprecedented level of functionality, reliability, and sophistication. This gyro performs best when used with non-Digital servos. sml 2/1/01 jxs 2/21/01 ir/jl updt jxs 7/07/03 updt mcw 1/14/04 updt jxs 2/14/05 updated jpg 3/16/06