Comes fully assembled but requires digging a hole (approximately 1 hour installation time from start to finish). Simply install in the ground, drop in dog waste, and occasionally add Digester Powder and water for continuous break down of waste. Works like a home septic system by using Enzyme and Bacteria action to turn waste into a ground absorbed liquid. The Eco-friendly Doggie Dooley is harmless to lawns, pets and shrubs. Each unit comes with a starter supply of Digester. Inside the Doggie Dooley the fast acting chemicals break the waste down which means never having to take out smelly trash bags again. Doggie Dooley utilizes the enzyme and bacteria action reducing dog waste to a ground absorbing liquid. Includes a 6 month supply of Digester Powder. Works well in all soil conditions except hard clay or heavy sand For up to 2 large dogs or up to 4 small dogs. Tank diameter is 14". Lid opening is 8.5". Septic Tank Style - waste is treated in the tank, then overflows. Galvanized Steel tank with durable polyethylene plastic lid. Foot operated lid opener comes completely assembled.