This Gamma 20 x 16 Ft. Tongue and Groove Log Cabin is one of the internally brightest log cabins. It comes, as standard, with four full pane opening windows. The windows and doors comprise toughened glazing units, ensuring maximum security, safety, and peace of mind. Also, equipt with the Gamma log cabin is our standard heavy-duty mineral felt - meaning all you need is a prepared level base and your preferred preservative.