The Cooler Fan Blade comes with an Aluminium Insert with an ID of 12.82mm and an adjustable screw.We at SURJIT MOULDS & TOOLS PVT. LTD are in the business of Air Coolers for over a decade and we really understand the pain points of an AI Cooler customer.Hence with our spare products we want to provide the consumer a solution.All our spare products are thoroughly tested to ensure best result.The Blade is made of ABS Plastic and has a diameter of 16 Inches.In order to maintain the performance of the Air Cooler we recommend that you buy our Cooler Boy to ensure that the Air Cooler stays dust free when not in use.Our Plastic cooler body ensures that all the critical components of the Air Cooler remain safe and free from dust and moisture.