Historical information
Japanese style box bellows (fukisashi/吹差鞴) reached their current and finalized form by about the sixth century. They are constructed almost entirely of wood and allow a smith to supply a highly controlled air blast to the forge by pulling and pushing the handle slowly back and forth. Using dual chambers and two sets of valves, the air is supplied on both the push and the pull stroke, and the blast may be highly intensified or stopped in an instant as needed by the smith.(http://islandblacksmith.ca/2015/06/why-you-need-a-swordsmiths-fuigo-box-bellows/, accessed 18 February 2018)
Physical description
Timber box with handle on the side which pulls out.