20pc Fireworks Heavy Wall Cardboard Tubes 1" x 4" x 1/8" 37mm

They fit almost perfectly in 37 mm launchers

These are slightly under bore if you’re using them for 37mm reloading, but that’s nothing duct tape won’t fix. The 4” length is perfect for drag stabilized bird bangers, and the reduced width can save materials, and possibly even propellant, while leaving room inside the case for modifications like guidance fins.

As described

Great for scouptures and school work

A great little tube for your hobbies.

These are great for doing different science projects with my kids .. we use them for making sugar rocket motors as it's fun with the kids and it seems like you get more lift on take off...

Others available for less money

fun