Brass base with adjustable bands include star accent on each side while top has silver luster clip to hold a litmus paper insert. Originally this would change blue to pink according to the humidity. Litmus is gone, but replaced by stiff paper to keep the holder clip in position. New humidity sensitive paper could easily be inserted. N. Mint value in Hake's Official Price Guide to Pop Culture Memorabilia is $450.00. The metal parts here are N. Mint but as original litmus paper is gone we've priced substantially lower. Quite scarce.