14 SPEED ADJUSTMENT: 1st gear 77 to 86mm or min, 2nd gear 115 to 121mm or min, 3rd gear 152 to 158mm or min, 4th gear 190 to 220mm or min, this glass glue gun offers the perfect speed for both professional engineering installations and home DIY projects. 2AUTOMATIC RETRACTION SYSTEM: The motor is equipped with an automatic retraction system to prevent leakage when the gun stops. When the trigger is released, the motor instantly reverses, releasing pressure on the tube. This feature is a game changer for keeping the workshop and projects clean. 3WITH LED LIGHT: The built in LED light at the barrel end is a great feature when working in attics, crawl spaces, garages, or other dark areas. It provides sufficient brightness to notice the flow and joints of the sealant. 4SMOOTHLY AND EFFICIENT OPERATION: With the lock button pressed during the glue stick advancing process, you can smoothly and quickly dispense a smoothly flow of adhesive. In professional scenarios, using the four speed setting, you can complete one glue stick in about 2 minutes, significantly improving work efficiency. 5VERSATILE APPLICATIONS: This glass glue gun is suitable for various home renovations, kitchen countertop installations, shower product installations, floor repairs, and caulking.