This kit is simply a collection of compatible, high quality spares that saves you the time and effort of sourcing all the correct size parts individually. Please note that these O rings and springs are unofficial spares. A handy opening tool is provided with some options. Package IncludedAs Picture Small O ring (Viton chemical resistant) Large O ring (Viton chemical resistant) Spring (316 marine grade stainless steel) Tools Please note that you are responsible for the fitting and troubleshooting of the spares as you see fit. Although we recommend only changing the o rings if it is necessary, especially the small o ring due to the risk of damage to the plunger. There are some variations out there and the groove for the small O ring is bigger with some models so we provide two sizes of small O ring to fit all variations.