Aqua Kem Blue is Thetford's premium waste-holding tank additive. The advanced formula offers the best performance and odour control for your cassette toilet.Add 150ml and 2 litres of water to give best results in a 20 litre cassette. Features Assists in breaking down solids. This formula lasts longer than the GREEN formula, but is NOT suitable if you will empty into Septic Tanks Child proof cap Easy measure markings on side of plastic bottle Specifications Model: T30111 Cequent Lasts 4 to 5 days Use 150ml to a 20 litre cassette Not suitable for septic system or composting toilets Shipping Weight: 2.40 Kgs. Shipping Dimensions: 33 cm x 11 cm x 11 cm.