I made these for this past Halloween for a demon/fallen angel costume. The base is a one-size set of sparkly black bat wings from Spirit Halloween. I hot glued the feathers and snakes to the base to give them a "freshly fallen" look. The straps are made out of a stretchy clear rubber and work like bra straps. If you''re good with sewing, you could probably upgrade them! Only worn once to a party and would love for them to get more use. Great for Halloween, cosplay, conventions, etc. See pictures for wing span measurement.