Clay Flue Liner 8 3/8" x 8 1/2" Catalog Chimney Items Clay Flue Liner 8 3/8" x 8 1/2" SKU : 88CL Description Concrete Chimney Block | NYS Tek Spec 3.5 | Heat Stop Refractory Outside Dimensions: 8 3/8" x 8 1/2"Spec Sheet Rates Please contact us for current pricing and availability. Request Availability