This illustration applies to all barrel diameters from 1 - 2". Barrel sizes under 1" need no special loading nor do they need caps or lifters. Caps and lifters are optional with 1" hand held units, but are mandatory on all 2" CO2 cannons. The use of caps & lifters are optional on 3 & 4" air cannons barrels, but should be used with CO2 systems. For detailed information refer to your original product instructions.