This is the HO Scale Curved Tunnel for Your Model Railroad Layout from Woodland Scenics. FEATURES: This flexible tunnel is realistically painted Two shades of grass on the sides and brown gravel on the top of the tunnel Tunnel portal is painted gray Designed for an 18" radius but allows for 15"-22" radius Ready to use INCLUDES: One HO Scale Curved Tunnel REQUIRES: Adhere tunnel to layout Hydrocal, flex paste or white glue Hobby knife, sandpaper or file Earth color liquid pigments SPECS: Scale: HO 1/87 Size: 25-3/4"L x 15-1/2"W x 8"H (654mm x 393mm x 203mm) Portal opening: 2-3/4"W x 3-5/8"H (70mm x 92mm) COMMENTS: Hydrocal is a product of U.S. Gypsum. For further information on installing tunnel portals, as well as complete instructions for creating landscape and terrain, read "The Scenery Manual" (WOOU1507). tlw 12/13/07 ir/jxs