BeadBoxers cornerbead kit fits on all brands of rectangular-axled flat boxes (i.e. Ames, Columbia, Drywall Master, North Star, Tape Tech) and allows drywallers to use flat boxes to coat cornerbeads and flats seamlessly. BeadBoxers can be used on all types of cornerbeads and once installed, do not need to be removed for coating flats. The product retrofits the flat box axle-and-wheel configuration, providing a stainless-steel disc that aligns and guides the box down cornerbead, and an axle clip that works in conjunction with the disc. It more than doubles the productivity of flat boxes by enabling use on both flats and cornerbeads effectively.