Each kit includes a Teflon sealing ring kit, converter seal and a high tech pump to case seal that prevents unwanted leaks. These are the exact components used in all DYNAMIC C4's. From high dollar upgrades to the most basic build ingredients, attention to detail is key for a long transmission life. In this case, the Teflon ring kit provides superior sealing while avoiding 'ring groove' that can be caused by oem rings combined with the added line pressure of a competition valve body. High pressure can also aggravate the sealing conditions of the pump to case gasket. Aside from necessity of clean, unmarred surfaces, the upgraded pump gasket in this kit plays a big part in heading off a dreaded plume of white smoke as transmission fluid pours out the front of a freshly built transmission and onto the exhaust! A slightly thicker gasket of a superior material does the trick here. Do it right- do it once!