Delayed Action Door Holders created the Doordwell in 1984. It is a simple delayed action door holder which comprises a simple air bleed sucker device, which is fail safe.
It holds open sprung doors for stretchers, wheelchairs, trolleys etc. The time delay before closure is adjustable simply by the turn of a screw. Unlike expensive electro-magnetic devices, which can cost hundreds of pounds per door, the Doordwell is simple to fit and inexpensive. They remove the use of illegal wedges to keep your door open.