This LED Driver is used to power low voltage (12v) LED bulbs and is ideal for use with LED Strip Lights. LED bulbs require a constant current to work properly. This transformer is suitable for our 5 meter strips that operate 25W in total, with LED bulbs. This Driver is both a constant current and a constant voltage driver. This LED Driver is the perfect product to replace the 12v transformer which is currently powering your existing low voltage strip lights. This driver can also be used in conjunction with LED controllers for strip lights. Stipe lights generally require between 5 - 10 Watts per meter depending on the type of strip light. Please look carefully the power requirement of the strip light and select the appropriate transformer.