Simple dimmer kit for using at AC 220VOLTS FOR FAN / LIGHT ETC. We use triac BT136 600W and also same supplied with kit. Best untill 400 W , I used. If you want to use more than 400W the replace the triac and use BT 137 / 138 / 139 as per your need or best to use our INDUSTRIAL DIMMER 2000W. Very best kit.