Timberland City 6" Zip Boots - Men'sPerfect for your feet. Even better for the environment. The inspiration behind the Timberland Earthkeepers City 6" Zip Boot is born out of a desire to create a greener, outdoor-tested boot with a smaller environmental footprint. This boot features a premium burnished leather upper with an inside zipper. The inside lining is made from organic cotton canvas and recycled PET mesh fabric. This boot also includes a Green Rubber? sole made from 42% recycled rubber.