The Long Crack Repair Slider Complete is the tool most aligned with long crack windshield repair. This tool comes as part of the Crack Master Repair Tool Complete Bridge and this is the only tool on the market that can actually repair long cracks in a windshield to pre-loss condition. What this tool is engineered to do is basically repair the long crack from the surface as it slides along the glass to fill the long crack with thick structural adhesive resin. The long crack slider tool is created with other features that ensures you get a smooth injection of resin with no glitches. The bar is the wonder bar and has self leveling bolts that is a key part in keep your tool stable when sliding across the windshield. Normally if you have a professional crack master kit, you have the ability to have this tool isolated. WIth the standrad kit you can split the bridge apart in order to convert to a long crack slider and crack-opener setup. If you're in the windshield repair business already and need more versatility, then what you're going to need is the Professional Windshield Crack Repair Upgrade Kit to have the long crack slider isolated on its own and another crack opener to fix more than one vehicle at a time or fix a long crack and or stone break in one windshield.