To fasten greenhouse plastic, bird netting or shade cloth to PVC frames, especially where wind blows coverings off. Easily snap over PVC pipe – select clamp size to fit pipe diameter. Space clamps about 1 ft apart. Use additional clamps in windier situations or use aluminum row cover snap clamps to make the PVC snap clamps grip tighter. Fits 1″ PVC pipe. Dimensions: 4″L x 1.5″W x 1.25″H These clamps are heat sensitive and may lose gripping strength if exposed to temperatures greater than 140F or 60C. Warning: This product or its packaging has a CA Prop 65 Warning