The BT-50 model rocket body tube is probably the most common size of body tube. The BT-50 can be used in a rocket with an engine mount kit for A-class, B-class, or C-class model rocket engines. The BT-50 can also be used directly with a D-class, or E-class engine for rocket designed for high altitude flights.

• Inside Dimension: 0.950"
• Outside Dimension: 0.976"