As name suggest, Kashmir willow bats are cricket bats made in Kashmir. Some of the districts where these bats are made in Kashmir are Anantnag, Baramula, and Pahalgam.

Generally considered heavier than English willow bats, players of the sub-continent prefer these bats because they generate greater speed. The industry, established in Kashmir, combines traditional tools with modern technology.

Kashmiri bats require constant knocking and oiling to make the bat good enough to use in a cricket match. Knocking makes the fibres of the willow blade compress together, which helps the bat bear the impact of the ball. Constant knocking for six hours is required so that the edges of the bat are well shaped. Another major aspect of taking care of such bats is oiling. Oil is applied on the back, toe, front and edges of the bat to make it more durable and to ensure the fibers get knitted properly.

source: http://en.wikipedia.org/wiki/Cricket_bat