Easy Stackable Placement with Glazelock patented collapsible locking mechanism; won't rot, shrink, or swell Simplifies alignment of multiple shim applications in window, door installations, curtain walls and more Eliminates the need to tape or glue shims together Fit around bolts and anchors, provide a secure and stable stacking solution Glazelock quality and durability is trusted by high performance professionals across several industries Glazelock Shims Inc. has been a manufacturer of structural plastic shims since 1997 supplying the professional and DIY Window, Door, and General Construction Industries. Glazelock shims were invented by a window installer, for window installers and more. His goal was to create a leveling product that reduced his material and labor costs, was safe to use, and ultimately would create an improved installation, setting his company apart from the competition. He wanted to simplify installation across many indoor and outdoor applications and appeal to industry-wide tradesmen for window installations, cabinets, counter tops, doors, tile, plumbing toilets, decks, landscaping, industrial machinery, and many more. Setting, leveling, and finishing a project accurately with the best craftsmanship is something to be proud of everyday. At Glazelock, we pride ourselves with quality products that stand the test of time, quick turnaround time, and great customer service. All of our products are Made in the USA.