Studio Pro Burnisher Combo Pack contains 2 specially designed plastic fids used in leaded glass and copper foil stained glass. The thin, straight burnisher is used to press and burnish the copper foil tightly onto the glass surface to facilitate a smooth, even surface for soldering. The unique hook-shaped fid is used to widen lead channels to accept a slightly thicker glass, and the flat end is used to press leaded glass putty/cement into the channel to stiffen and reinforce the leaded glass panel.