Shuttle S01 Acoustic Fire Door Retainer is brand new to market and is an excellent choice for fire door retaining problems.
It's always been tempting to wedge open fire doors. Often, ironically, with a fire extinguisher. This is dangerous and could result in fire insurance becoming void and the personal prosecution of directors, partners or proprietors of offending businesses and organisations.
What's much worse is that wedging open doors allows smoke and fire to travel much more quickly throughout a building.