The Briggs B357108 flush valve comes complete. The flapper comes with this flush valve also. Therefore the flapper with the chain and hook are complete. The flapper is plastic. However it has a rubber seal that prevents leaking. Also the valve itself is plastic. Therefore it will not rust. The nut and gasket come with this flush valve. They prevent leaking at the bottom of the valve. 

The Briggs flush valve comes complete. Therefore It is ready for use. The chain and hook come with the flapper. The flapper is installed on the valve. Therefore it needs to be connected to the lever. Also the lever lifts the flapper which causes the flush. The gasket at the bottom goes against the tank. Therefore it prevents leaks between the tank and bowl. The nut comes with it. 

The Briggs B357108 Flush Valve comes complete. In conclusion, It comes with the complete flapper. Which has the chain and hook. The flush valve gasket comes with it also. Therefore it can prevent leaks. Also the nut for the flush valve comes with the valve. This fits tank models 4140, 4142, and 4143. 

• Genuine Briggs Replacement part
• Comes Complete
• Flapper with chain and hook
• Rubber Gasket
• Plastic Nut