Manhole opening device is used exclusively to allow occasional access to the roof, for example in case of maintenance.
The opening is actioned from the inside with a locking/unlocking handle provided with one or two gas springs depending on the size of the dome. These gas pistons help the operator to open the dome until reaching an 80°-90° angle.
Upon request the opening from the outside is available.
For continuous skylights, manhole opening device is available with clear span 120 cm maximum.