You can?read?the user's guide?from the photo gallery on the left、?which?explains?how this unit works.?Note that the following information is provided by the manufacturer. .?- Saves 20% to 30% of electrical consumption- Stabilize the supply voltage- Reduce electrical overheating and enhances lifespan of appliances- Easy to use、 maintenance free- Earth friendly.?Rated voltage input: 90V-250V Rated frequency: 50HZ-60HZ Load capacity: 15000W                                                                                                                                 Dimensions: 4.53 in x 2.68 in x 2.24 in<br />Weight: 6.24 oz