Mantis starter clip, 25 pieces per clamshell includes screws. The newest generation of deck fasteners, featuring Mantis technology provides a hidden fastener solution for grooved decking made from PVC (polyvinyl chloride), composites, or wood products. Features include no visible fasteners, unique starter and finish clips ensure and unblemished deck surface; reduced potential for mildew and rot, clips elevate the deck boards off joists for proper airflow and drying; uniform installation and appearance, clips automatically space deck boards 3/16" to help ensure even spacing; high strength steel fasteners, unique coating process for corrosion resistance. #2 square drive screws included with clips. Recommended for use with ACQ (Alkaline Copper Quaternary) and other treated lumber joists. 30 year limited warranty against loose deck boards, leading performance in hold down and lateral movement.