Rock-It System 3.0 employs a streamlined design, utilizes North-South adjustability and provides an extremely fast, easy, no-hassle installation. Conforming to UL 2703: First Edition, Rock-It System 3.0 retains the unique top-down leveling that installers appreciate, and was designed for a faster, easier installation. Testing performed by Nationally Recognized Testing Laboratory TÜV Rheinland.