Twin thread (Telescopic) screwjack with the large bracket set, made in solid brass and laquered to maintain the finish, twin thread screwjacks have an inner and outer thread that extend together, the advantage to this the screwjack does’t protrude out to far keeping the installation neater.
This is the larger of the 2 screwjacks we stock, both types are most popular on roof vents and skylights. The large bracket set is most often used on upcv conservatories where there is no visible frame on the opening vent.
The bracket on the body can be turned round if needed, you can also mix the bracket types if needed for your window frame.