Aviation Laboratories Aircraft Wing De-icer used on HS-125 Hawker and Cessna Citation II series aircraft and several other newer aircraft models is approved by British Aerospace and meets DTD-406B. This product is tested before and after blending and undergoes strict quality control. Approved for all TKS systems. Filtered to 1 micron. Certificate of analysis and strict lot control. Part number AVL-TKS-5gal includes one (1) 5-gallon pail of TKS Fluid.