*Lid size is 26" x 26" and is made from strong 24 gauge 100% 304 steel
*Outside base size is ACTUALLY 20" X 20" and is made with 18 guage 100% 304 steel
*Set screws are 2" long and adjust to fit the different variations in flue sizes
*Fits any outside tile dimensions between 18" x 18" to 20" x 20"
*Base is designed to fit square, round, rectangular or oval flue tiles
*Screen is 8" high and has a 3/4" mesh screen
*Made in the USA and carries a lifetime warranty