The curved top extensions are designed to stop dogs from jumping and/or climbing over an existing fence of nearly any type that is at least 4 ft tall. Extensions can add up to an additional 2 ft of height to an existing fence. Each 100 ft kit includes: 12 - Curved Houdini-Proof Fence Extensions and associated hardware 1 bag of Heavy-Duty UV-rated zip ties (100 ties per bag) 100 ft of 42” tall welded wire fence material Written Installation Instructions Note: Fasteners for installing extensions to an existing fence, wall, building, etc. are not included. Fasteners should be chosen based on the fence type, or the material of the building, wall, etc. Keep in mind that every fence is different and some configurations may require fewer or more components than those included in the kit. Each kit includes components for the average fence of 100 linear feet with extensions spaced 8-10 ft apart. For example, important areas to consider that may require additional components are gates, corners greater than 180 degrees, and endpoints. Multiple kits can be purchased for larger fence configurations.