This plastic collecting jar is a must have item for insect collectors.  Traditional glass collecting jars are heavy and fragile. These collecting jars are clear, shatter-resistant, and lightweight. They are recommended for those planning collecting trips or youngsters. The jar is constructed of a special PET plastic that is resistant to ammonium carbonate and to ethyl acetate, the most commonly used insect killing agent. The jar uses a cartridge to contain the killing agent. The porous hard plaster cartridge securely encloses the killing agent yet permits fumes to seep through into the jar. The cartridge screws into an inner metal lid riveted to the widemouth jar lid, and does not crumble or break with normal use or in humid conditions.