Charcoal Soldering Block 7 X 4 X 1-1/2" Individually Boxed Orders over $100.00 are usually shipped within 24 hrs of receipt (excluding weekends). The estimated delivery dates showing on Amazon are usually delivered much sooner than the dates shown. A time proven technique for effective soldering. Under flame, the charcoal glows and reflects heat back in to work, making the flame more efficient. Select, close-grained, knot-free wood is chemically prepared with a special process for soldering. Easily punctured to hold work. (Not heat rated). Free Shipping!!! Used by Professional Jewelers