#15 O-ring spacers for mash tun conversion

These are spacers for #15 O-rings for use on the outside of a igloo or similar cooler to mash tun conversion. These are different sizes, and are designed around a 1/2" plumbing hardware.

these compress an #15 O-ring to the outside of the cooler, and take up the gap to the ball valve so you can avoid stacking washers, especially where washers don't have a great fit in for 1/2" plumbing pieces.