Allows you to use 3 or 4 prong drive-in T-nuts, flanged nuts or standard nuts as wing nuts.

The diffrent between the 3 and 4 is just the mounting holes for the T-nuts, other nuts will work on either and the 3 prong is slightly smaller of the two.

You may need to press in the nuts to get a good connection, either screwing into something or using a vice should work.