Vacuum Design The unique vacuum design of the windscreen Repair Kit prevents air from seeping in between the gel. Vacuum the cracks before injecting the repair fluid. It can perform permanent airtight repairs on most laminated windscreen. Resin Easily Enters Cracks Windshield crack repair designed with a reinforced injection sealant dispensing head, advanced resin formula, can produce a strong pressure. and it has a vacuum function to quickly remove air from the crack. Easy to Use Clean glass surfaces before maintenance, then squeeze windscreen repair fluid into cracks. After squeezing, put the car in the sun to dry, and it sets quickly. After 10-20 minutes, scrape off any remaining repair solution with a spatula. ATTENTION 1. Take care that there is no water in the broken area before repair (water in the broken area cannot be repaired) 2. Do not repair in the open air, as UV rays during the day will cause premature curing that cannot be repaired. Please work indoors, in underground garages or in sheltered repair locations. 3. The damaged area must be dry and clean and free from dirt 4. The repair solution must be placed in the sun after penetration to absorb UV rays and produce a focal reaction before curing