In the E-61 Grouphead used on Isomac machines (and some other brands as well).
One of these springs is located under the mushroom valve, and one is also in the middle section of the Grouphead.
For a complete Spring replacement on your Isomac Grouphead, you will need to order 2 (two) of these springs, plus 1 (One) Drain Spring and 1 (One) Lever Spring.
