Feature: 1. Higher Accuracy: Wide in speed adjustment range, the DC motor speed controller ensures the stable working performance with high efficiency. 2. Standard Design: Supports AC input and DC output, the motor speed regulator enables direct start up when there is DC voltage. 3. Reversible Uses: To reverse the CW and CCW rotation direction of your DC motor, you can changing the wiring between M+ and M- terminals. 4. Wide in Fitting: Suits perfectly for 50W, 100W, 120W, 200W, 300W, 400W and so on, the motor speed control switch has flexible application. 5. Easy to Install: Compact in size and light in weight as well, the DC motor speed controller is very convenient to install within minutes. Specification: Item Type: DC Motor Speed Controller Overall Dimension: Approx. 100 x 60 x 114mm / 3.94 x 2.36 x 4.49in Opening Size: Approx. 81 x 53mm / 3.19 x 2.09in Installation Method: Panel Screw Installation. Package List: 1 x DC Motor Speed Controller