Your breathable waterproof footwear can get sweaty and wet inside when used in damp or wet conditions. If the outer fabric or leather absorbs water, the breathability of the footwear will be reduced. The Durable Water Repellency (DWR) of your footwear will eventually wear off, so must be maintained to ensure your comfort and the footwear's effectiveness._Nikwax Fabric & Leather Proof adds Durable Water Repellency (DWR), which prevents water absorption, whilst maintaining breathability. It's completely non-flammable, contains no volatile organic compounds (VOCs) and is fluorocarbon free. _ Specifically designed and optimised for fabric and leather combination footwear, it leaves a flexible water repellent treatment on individual fibres, allowing moisture vapour to pass through, maintaining breathability and keeping your feet dry.___Nikwax waterproofing products are WaterBased, non-aerosol, non-flammable, non-hazardous and environmentally friendly. You don't need to wait for your footwear to dry before application.