This is a neat find. An old metal water filled bed warmer, with a brass screw cap. Appears to be all hand forged. These were filled with hot water and slid under the covers to warm the bed. Some were even filled with oil and heated as oil kept hot longer. In Japan they call them a Yutampo, and use them for heating the beds as Japan winters are extremely cold. This one is 12" in diameter and is 6" thick, plus the nice thick bail handle. Original brass screw on cap. This would be nice to even use today to toast up your tootsies on a cold frosty night. There are a couple of small dings, but no leaks. How is it that our modern culture has lost such simple basic things as these, that bring us such comfort?