You can easily fasten both commercial-grade and standard-grade lights to buildings and trees with these tie wraps. They can be used with C-7 Lamps, C-9 Lamps, and Mini Lights. The Ties work for both standard Incandescents and LEDs. Each tie is 8 inches and the black color is designed for use with black wire and for night displays. Come in bags of 100. They are good for both indoor and outdoor use.