4130 aircraft grade seamless cromoly tubing. Ideal for tandem boom/bottom tubes in the perfect dimension for attaching to 68mm wide BSA English and 66mm wide Eccentric bottom bracket shells or any other use including heavy-duty mountain bikes. Light, strong and extra stiff. US made and ovalized in house. Custom lengths/sizes available. LENGTH: 762mm (30in) MATERIAL: 1.750 x .035 seamless 4130 steel DIMENSION: oval is approx. 52mm width x 36mm height WEIGHT: 737g at full length