Estes Rockets 3175 BT5-BT55 Centering Rings, for Model Rockets, (26Piece)

Includes 26 centering rings in 5 different sizes. Bt5, Bt20, Bt50 and Bt55. Perfect for making your own engine Mounts! 26 centering rings8 each. Bt5 to Bt20.4 each. Bt5 to Bt50.8 each. Bt20 to Bt50. 2 each. Bt20 to Bt50 - 1 inch long. 4 each. Bt50 to Bt55.