These are considered Sub-miniature servos The servos are made by Hitec. On all Hitec servos the Black wire is 'ground', the Red wire (center wire) is 'power', and the yellow (third) wire is 'signal'. This servo has a Hitec/JR connector which mates directly with a 0.1" 3-pin header. This servo comes with servo arms.
These are HiTec HS-422 Servos for use in any application.
1/4" Hex Size, 2" Length, 4-40 Thread Size
The B3 Compact charger is a very simple to use charger for 7.4 2S and 11.1 3S battery packs. No need for additional power supplies or 12v batteries as this little unit has its own built in power supply that can be powered with 100-240v.