25 pack of black Pinlock electric fence insulators for use with wooden fence posts. Simply nail the insulators to you wooden posts. Wire is easily inserted staight into pinlock insulator. Accomodates all types of fence wire including high tensile, smooth, and poly wire. Pinlock is ideal for high tensile fencing, and can be used with other fencing applications. Two nail installation keeps insulator securely fastened to post. Provides long arcing distance protection from wire to post. U.V. portected to resist weathering.