This block is 2 3/4" x 5 1/2" and 1 1/16" thick. Charcoal blocks provide the ideal surface for soldering metal. The natural charcoal block tends to crack under the heat of the torch so it is advisable to bind around the edges using a thin steel wire to hold it together in case of breakage. The block retains and deflects the heat of the flame back onto the piece that is being soldered, making the torch more efficient and soldering steps go faster.