1 – 12oz (355ml) container. Carbon Guard is a gasoline additive formulated to minimize deposit build-up in 2-cycle and 4-cycle marine engines when used as directed. Carbon guard will provide: 1. Reduced possibility of piston ring sticking 2. Reduced carbon build up on 4-cycle valves 3. Better overall engine performance 4. Increased engine life. For 2-cycle Engines – Add 1 oz. of Carbon Guard for every 8 gallons of gasoline. For 4-cycle Engines – Add 1 oz of Carbon Guard for every 16 gallons of gasoline. Note: Engine with an excess of 100hrs of operation and not previously treated with Carbon Guard should be treated with Evinrude Johnson Engine Tuner before beginning us of Carbon Guard.