1 1/8 in

Multi-Spec Compatibility: The mtb stem fit 31.8mm handlebar (100mm circumference) and 28.6mm (1-1/8") steerer tube. The handlebar stem feature a -60° to +60° angle range and lengths of 100mm 110mm 120mm 130mm 140mm. Includes 2 hex wrenches for easy setup Lightweight & Stiff: This mountain bike adjustable stem is a CNC-machined aluminum bicycle handlebar stem riser that combines low weight with high rigidity. Trust this durable bicycle adjustable stem to tackle challenging rides and go the distance Comfortable & On-Demand Adjustment: BUCKLOS adjustable bike stem allows for on-demand customization of both height and angle, enabling you to create your ideal and unique riding position. Reduces strain on hands, back, and shoulders on long rides Easy Installation: BUCKLOS adjustable handlebar st.