ORIGINAL: RCKen
You won't need anything like this to keep a glider level. Most gliders are rudder only and the dihedral in the wing will keep the glider level. You won't have to do anything to level the wings at all.
Ken
Recently I have been getting all kinds of tossed around and have to pretty much give constant rudder inputs. But often it gets so high I really not sure which way I am being tossed around.
I expect I could thermal more efficiently if my wings were dead-on level wing. Right now I often cannot tell if I am nearly dead-on level or banking 15-degrees. Maybe these leveling devices are not precise enough to keep a plane anymore than 15 or 20 degrees level? I do not know.