KDS820 Dual Rate Head Lock AVCS Gyro for 450 500 600 700 RC Heli Remote Control Toys Parts Brand: KDSMODEL . Model: KDS820 . Color: Black . Material: ABS . Weight: 0.67 oz (19 g) . Dimensions: 1.06 in x 1.06 in x 0.51 in (2.7 cm x 2.7 cm x 1.3 cm) . Compatible device:Align TREX 200 250 450 500 550 600 700 helicopter . Functions: Gyro operation direction switch, DS mode switch, control delay trimmer,limit trimmer, remote gain control, AVCS/normal mode switching . Features: Sensor: SMM . Operating Current: 30mA . Operating Voltage: 4.8-6V . Packing Includes: 1 x KDS820 Head Lock Gyro . 1 x 3M Sticker . 1 x Screwdriver . 1 x Manual .