The Flat Bamboo Winnowing Fan is a traditional tool made by various indigenous tribes of Northeast India, especially the Mishing tribe of Assam. This simple yet highly effective flat square-shaped basket made out of bamboo is handily used in the winnowing process wherein grains are separated from chaff by the action of wind.
The Flat Bamboo Winnowing Fan is an event of agricultural utility mainly at harvest time when the tribe separates rice and other grains from the husk.The construction of the winnowing fan consists of four split pieces of bamboo forming the edges of a square basket. These pieces are firmly tightened with using bamboo straps, which results to strengthen the rim on all four sides. This method of construction is meant to offer additional strength whereby the fan can endure past uses without loss of shape.

The flat shape of the fan allows it to catch wind very effectively when tilted so that it can carry off the light husks along with the heavier grains. The flexibility and strength of the bamboo afford it a finish fit for maintaining function even in the outdoored conditions applicable in the tribal region. Slippers are mainly used for winnowing rice and other grains. The Flat Bamboo Winnowing Fan is indicative of the Mishing tribe's resourcefulness with materials available locally to fulfill day-to-day tasks. It embodies much more than care and craftsmanship, for it incorporates inspiration from strong and functional designs - lessons that a tribe understands from being agricultural and sustainability in natural resource use.