Flambeau Turkey Heavy Metal Box Calls Box in uniquely contructed of black, anodized T6-6061 aircraft grade aluminum Underside of American walnut lid is coated with a proprietary formula that makes this box call waterproof and chalk-free Lethal combination of wood and aluminum yields realistic high pitched turkey calls peaking over 15,000 Hz Hardwood end blocks are angled to produce a different pitch on each side of the box Aluminum box can be "tuned" by varying hand position