ACTO® Steam Chemical Integrators are chemical indicators consisting of a paper wick and steam and temperature sensitive chemical tablet contained in a paper/film/foil laminated The chemical tablet melts and migrates as a dark color along the paper wick. The migration is visible trough a window marked REJECT or ACCEPT. The extent of migration depends on steam, time and temperature. This product is also available with an extender strip affixed to one end of a ACTO® Steam Chemical Integrator and is labeled as ACTO® Steam Chemical Integrator. The affixed extender is a 19 cm long by 1 cm wide , paper strip that serves as a handle to retrieve processed integrators from inner packs.