The saVRee four stroke engine utilizes two suction inlet valves and two exhaust discharge valves. The suction valves supply ambient air to the combustion space whilst the discharge valves discharge the exhaust gas to atmosphere.

The fresh air (intake) valve is larger than the exhaust valve to ensure fresh air replaces as much exhaust gas as possible within the combustion space.

The type of valve shown is often referred to as a poppet valve.

Encyclopedia - saVRee