2.6" - 38mm (64.9 - 38mm) centering ring holds 38mm motor tube inside 2.6" airframe. 1/4" plywood.

Fits into any 54mm airframe. Works best with Rocketarium 38mm (S), LOC and Madcow 38mm Cardboard Tube, Blue Tube (41.6mm motor tube OD)

- 41.6, - 64.75mm,  6mm,  7g