This post contains affiliate links. As an Amazon Associate I earn from qualifying purchases Stoker tandem bike stem, a famous adjustable stem, is made by 3D forged al 6061, providing ultra strength. Product Features Material: AL6061 Seatpost Dia.: 29.8/31.6mm handlebar: 25.4/31.8mm Length: 190-230mm/215-255mm Angle: +35 degree This post contains affiliate links. As an Amazon Associate