I choose cages with both vertical and horizontal bars on cage sides which I have, but are small and separate. Now hard to buy since Covid and very few coming in, largely blocked from China. On saying that, of course I can add verticals around 2 sides of cage. Just have to think outside the box. I am now looking at 1 larger cage for 2 birds that hardly get along, but need their personal space so to speak. Diesel (1) is tame and outgoing, but 11 yr old Mollie is not and wants her personal distance from this young baby compared to her mate of 9 years who died last year. They need natural, crooked branches apart from straight, normal dowel perches. Just my thing to mimick what they may have in the wild.