Stretches to fit gates opening up to 20 feet. Retracts to keep gate off the ground when open. Electrified when closed, neutral when open. Highly visible and effective. Expando Gate assembly consists of One Rub’Rgate handle, one large galvanized spring, two pin-lock style wood post insulators with galvanized nails, two pin-lock style T-Post insulators, one anchor/activator, one fence line clamp/tap, and complete schematic instructions. Equipped to fit wood post or T-Post openings.