Schermer’s C-5 Blue Power Loads are blank cartridges For all “K” Series Schermer Stunners. C-5 Blue Power Loads replace C-21 loads and are used for Normal Size Bulls. Power loads are packed 100 rounds in a moisture-resistant plastic canister with ten canisters per case. Types cannot be mixed.These power loads cannot be shipped via air and are not returnable. The use of any other power load cartridge not manufactured by Karl Schermer GMBH will void the warranty of these stunners.