Set of 4 pcs O-rings suitable for most SunBox Catch Cups.
Use it to avoid dangerous atty pressure on the positive pin and on the board, to prevent scratches on the catch cup and the atty accidentally stuck on the base. It seals the atty avoiding issues with leaking atties and gives more stability to inaccurate threaded atties. Always use one of these o-rings to let your SunBox live longer.