New Grommet & Micro Jack insertion tool This five inch spring action tool makes the insertion of eyelets (grommets) a SNAP! The tool is used for both the copper tape and in making hardwire connections. One end is a center punch and the other is for the insertion of large grommets. It works so well that a pilot hole is not even needed but is still recommended. MDF is no match for this simple tool. Simply drill a 1/16th inch pilot hole through the flat tape wire, place an eyelet on the end of the tool; then pull back the spring and SNAP! It is the perfect answer to wiring on MDF hardboard and in getting a solid connection in copper tape; especially at overlapped joints.