Water Hawk is manufactured from a unique silicone compound to ensure it does not support microbiological growth. Water Hawk complies with BS EN 751-2 Class A. Water Hawk is used on all jointing applications, but is uniquely designed for use with potable water. If a reinforcing material is needed, an approved reinforcing fibre can be used with this product. An approved fibre should be used on pipework over 25 mm with Water Hawk.