A: Our 4 inch and 5 inch GLI tube kits are packaged with all of the necessary parts to be assemble both our aluminum AND resin Solar Reels. Each tube kit includes (2) Aluminum Tube Inserts AND (2) Resin Tube Inserts. These inserts are installed where the tube kit attaches to the Reel base. If you have our Whirlwind, Hurricane, Storm, or Monsoon Reel System, you will be using the Aluminum Inserts. You may discard the white Resin inserts that come in the tube kit. If you have our Cyclone or Typhoon, you will be using the white Resin Tube Inserts and discarding the Aluminum Inserts.