Excalibur’s patented shell making process delivers unrivaled color breaks and thunderous reports. 24 Canister Shells and 4 High Quality HDPE Tubes. This kit is definitely the most sought-after mortar shell available. This thing sounds like a cannon when it comes out of the tube. The lavish variety of effects and thunderous breaks make this a winner. These amazing World Class Fireworks shells have been the best selling canister shell for more than 20 years.