Body size: 14" x 9" x 4" Material: 409 Stainless Steel Inside Diameter: 2.5" Bi-Directional Black Widow Venom 250-series mufflers set the standard for development of our 300-series, Race Venom and Widowmaker mufflers. Made out of quality brushed stainless steel and a patent pending hourglass design, the Venom 250-series produces Black Widow's signature aggressive and clean tone – without a harsh drone sound. All Venom mufflers are backed by our Lifetime Limited Warranty.