Jessie even here all is not so simple Although not common Nelson plugs are 5/16 and button head plugs will have a host ring to fit the particular manufacturers head. The point here is new folks make many inappropriate purchases all the time and this can be very frustrating. Frequently it is caused by making the assumption that everything is 'standard' which is frequently not always the case. Instead its better to research things a bit before making in any assumptions, it can prevent a lot of frustration.