as far as i know...there isn't any harmful screen for a BD. the only thing that can be harmful is if they come into contact with it and they get their claws caught then ripped out. as long as it's a screen top you should have any probl;ems with any screens. i would just go buy a roll of the metal (not fiberglass) window screen from home depot or lowes. it's cheap and works great as long as they can't get up to it and climb on it.
i would reccomned a screen top for a beardie, although beardies are desert dwellers they benefit greatly from a little humidity as long as your temps are correct. i would suggest at least a half covered top or a fully covered top with small vent. all my tops are covered and my beardies have never looked better.i also do this for all my other reptiles too.
an all screen top easily creates a bone dry enclosure...which isn't good for them and retaining water in their systems.
just my opinions and thoughts, no need to change any thing.
hope this helps
trevor
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Trevor Bennett
E-mail: yruemailinme15@yahoo.com
yahoo SN: yruemailinme15
location: Salem, Oregon