Plastic clamp 2305019 (set of 50 pieces) is designed for round cable 20 to 26 mm Installation in wood is done by using wood screws Color: white Material: PP( polypropylene) Installation in wood is done by using wood screws No. 8-10 For installations in concrete, brick, plasterboard, etc, use TP plugs TP0, TP1, TP2 and wood screws, or TPS-5 nail plugs