Can I use screwjacks on my vertical window?
When screwjacks are operated with a winder pole, you have to position yourself with the screwjack pointing directly at you.  So, if your vertical window is at a high level, operation with a pole is not usually feasible as the winder pole will be above your head.  If the window is at a lower height, then screwjacks can be used, we have both handle and pole types.  One thing to consider is that the screwjack may extend into the room space when the window is closed.