In addition to regulating the generator voltage,the AVR circuitry includes under-speed and sensing loss protection features.Excitation power is derived directly from the generator termainals. Positive voltage up from residual levels is ensured by the use of effcient semiconductors in the power circuitry of the AVR. Provision is made for the connection of a remote voltage trimmer,allowing the fine control of the generator output Colour:Photo Color :plastic type:-DAVR-250S Package Contents: 1 x Automatic Voltage Regulator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.