Class-A Double Wall Insulated Chimney Pipe 8" x 9"The 8" inner diameter x 9" Long double wall insulated chimney pipe length is used to add length to your chimney stack and includes 1 Locking Band. FEATURES INCLUDE: Made of 304 stainless steel for superior corrosion resistance 0. 019" thick inner and outer walls (17% thicker than our competition) High Density 1. 18" thick ceramic fiber blanket insulation ensures no hot spots and no settling of insulation Precision Engineered Twist Lock connection for