These boxes are made with 2x4 frame, have 3.5” insulation on bottom and sides, 2” on top. It holds a rubbermaid 70 gallon tank ( included) and keeps water from freezing down to about 20 degrees. Add a 5 gallon bucket heater( not included) that only costs about $5/ month to run and keeps water open to sub zero temperatures. These cost me over 500 to build years ago! Dimensions are 48x42x32”