1：To join the seam, turn the side knob counter clockwise until you are satisfied with a seamless appearance. 2：To level the slabs, make sure ones of the blue head under the top knob is on the higher side of the seam and turn the top knob clockwise until the slabs are leveled. Usually you only need to use ones top knob to level. Use two when there are any expanding needs. Lift the rubber tab on the edge of the suction cup to release the suction after seam has been completed. 3：Extensive Use Cases: Ideal for lifting and moving materials such as granite, bricks, marble, slabs, and more. Perfect for application in yards, construction sites, roadwork, and various engineering projects. 4：Place the fixed (left) suction cup on the left slab. Place the movable (right) suction cup on the right slab. 5：Pump the plunger until the suction cup attaches completely.