This is a spring loaded eyelet insertion tool. It is made to fit Cir-kit's small eyelets. It makes your wiring connections a snap in your dollhouse wiring tape. Just place a small eyelet on the tip of the tool, and drive the eyelet into the tape wire to make your connections. The tool is spring loaded and it does all the work. No hammer or drill needed. We even include an additional spring, in case you need to adjust the spring's tension, for harder or softer wood.