BT-3.90 x 6.5"

This six-inch segment was exactly what I needed to extend my rocket's nose cone section, and the cardboard feels sturdy enough to handle the ejection charge. The fit with my 4-inch airframe was spot-on with no sanding required.

I needed a longer tube for my 4-inch Cyclotron build and this 6.5-inch section saved me from having to splice two shorter pieces together. The cardboard feels sturdy enough for the high-power flights I'm planning.

Cut this to length for my high-power rocket build and it fit perfectly into the airframe slot. The cardboard feels sturdy enough to handle the ejection charge without any flex.