*Lid size is 20" x 28" and is made from strong 24 gauge galvanized steel
*Outside base size is ACTUALLY 15" X 23" and is made with 18 guage galvanized steel
*Set screws are 2" long and adjust to fit the different variations in flue sizes
*Fits any outside tile dimensions between 13" x 21" to 15" x 23"
*Base is designed to fit square, round, rectangular or oval flue tiles
*Screen is 8" high and has a 5/8" mesh screen
*Made in the USA and carries a lifetime workmanship warranty