Semroc Centering Rings Fiber ST-7 to BT-55(2pk) SEM-CR-7-55
Laser-cut fiber rings which center a ST-7 motor tube inside a BT-55 tube
Especially useful for making a standard engine mount for BT-55 rocket bodies
ID= 0.759"
OD= 1.283"
Thickness is 0.05"