The principle is making glue tabs stick on the dent and use tools pulling the tabs and lift the dent. Big dent needs slide hammer or puller. Small dent needs mini dent lifter or pulling bridge. Use different size glue tabs to different dent. Use hot melt glue gun preheating a few minutes and smear hot glue on the glue tabs and stick on the core of dent. Wait for 5-15 minutes ( it depends room temperature) and pull it by hand make sure the tabs are strong stick on surface. Use a slide hammer or dent lifter or any pulling tools lift the dent, try many times. Drop glue remover or straight alcohol on the glues between tabs and car, remove the tabs and glue. Check the surface if there still has a dent, use a suitable tabs and repeat the above process.(it could use a line board to check, but experienced users could use it very well) When there is a bulge (over lift caused), use a tap down tool. Please tap lightly, or it will damage the car. Item Include: 1 x T-Bar 18 x Glue Pads1xSuction Cup Remover Return Policy All of our items come with a 30-day free return policy. If you need to return, please contact us, let us know the detailed problem and send us some pictures for confirmation. We reserve the right to refuse any returns for objective reasons. Shipping Policy All of our items are shipped free with tracking numbers. Orders will be shipped within 3 working days upon receipt of payment. Most orders will be shipped within 1 working day. In most cases, shipping takes 8-12 working days.