These 12 in. steel anchoring spikes should be used to anchor borders for any hardscape installations. The spikes are great for many other general landscape applications as well. (10) 12in. metal spikes are included per box. Suggested use rate for a standard paver edging installation is one spike every 1.5 ft. of edging. Suggested use rate for a standard landscape edging installation is one spike per every 2 ft. to 3 ft. of edging.