these servos are great for 450 heli cyclic. i got 3 of them on my cyclic of my exi 450 limited edition. they have great centering and they have little to no chatter of buzzing even at4.8volts i use them with a spektrum ar6100e and they are very responsive and they give very crisp snappy responses on rolls and flips. if you can get them get the metal gears becuse after about 10 to 15 cycles of hard 3d the white plastic gears develop some slop. but the metal gears stay slop free. i recomend them as a great sub for hitec 65mg and as a cheaper solution for the budget contious heli builders out there. get em and give em a try you wont be sorry.
you can buy this Flyermate D130M Metal Gear HeatSink Digital Servo (Blue) at http://www.swanghobby.com/
-Weight: 17 grams
-Stall Torque (4.8V):2.2 kg/cm
-Stall Torque (6V):2.5 kg/cm
-Operating Voltage: 4.8-6V