Eurorack Hardware 3mm slide nuts are the perfect solution for tight modular mounting.  Hate gaps in your rig?  These are the solution and are designed to fit in almost any rails on the market (we recommend Eurorack Hardware Modular Rails).  3mm is the most common size of screw offered with modules by most manufactures.  Don’t like slide nuts?  Check out Eurorack Modular Nut Strips for the easiest mounting solution.