This mounting kit includes 22 Concrete Tapcon Bolts and 22 Washers. The mounting option can be installed on pre-cast concrete surfaces. Meaning it is perfect for installations that already have a concrete area or a previous racking system. Simply attach the Lag Bolts to the racking system then screw them into the concrete. Simply use a hammer drill to make holes in the concrete then screw in the concrete bolts. This Kit is good for 10 solar modules of the IR-30 Racking Please Call 971-374-7829 Before Ordering