Speed Nubs Safety Bump Rumble Strips Kit: 2 Black Sections - Total Length: 39.5" Order for 2 Black sections - Covers 39.5" Each section is 19.75" long by 4" wide. Installing them together makes a 39.5" speed nub Low profile (5/8" height) | Black section made from Recycled material Great for low speed traffic areas: Schools, parks, shopping centers, parking lots and garages Included Mounting Hardware: 8 pieces of 3" spikes. (For a more permanent installation, please use your own mounting hardware)