2 of BT60 - 29mm centering ring holds 29mm motor tube inside BT-60 airframe. 1/8" plywood. Works best with LOC paper, fiberglass, Madcow and Semroc...

2 of BT70 - 29mm centering ring holds 29mm motor tube inside BT-70 airframe. 1/8" light plywood. Works best with LOC paper, Rocketarium, Madcow and...

2 of BT80 - 29mm centering ring holds 29mm motor tube inside BT-80 airframe. 1/8" plywood. Fits into any 2.6" BT-80 tube. Works best with LOC paper,...

1.6" - 1.1" (ID 38 mm - 29 mm) centering ring holds 29mm motor tube inside 38mm airframe. 1/4" plywood. Fits into any 38mm airframe. Works best with...

1.9" - 1.1" (29 mm) centering ring holds 29mm motor tube inside 1.9" Aerotech airframe. 1/4" plywood. Designed to center Rocketarium, Aerotech, LOC...

2.2" - 1.1" (ID 54 mm - 29 mm) centering ring holds 29mm motor tube inside 54mm airframe. 1/4" plywood. Fits into any 54mm airframe. Works best with...

2.6" - 1.1" (2.6" - 29 mm) centering ring holds 29mm motor tube inside 2.6" airframe. 1/4" plywood. Fits into any 2.6" airframe including BT-80 tube....

3.0" - 1.1" (3" - 29 mm) centering ring holds 29mm motor tube inside 3" airframe. 1/4" plywood. Fits into any 3" airframe. Works best with Aerotech...

4.0" - 3" (4" - 75 mm) centering ring holds 75mm motor tube inside 4" airframe. 1/4" plywood. Fits into any 4" airframe. Works best with PML and GLR...

Cluster centering ring, fits 3.0" airframe. (2) 29mm (1.1") holes. 3/16" birch plywood. Fits into any 3" airframe. Works best with Aerotech paper,...