A 20-way turned pin SIL header from TruConnect, designed to be snapped to the desired length for use as headers or as miniature connectors in conjunction with SIL sockets.
If you want to be able to disconnect the motor in a Model Locomotive, or connect Tender pick-ups to the Engine then these are ideal. Small enough not to interfere with the action of "00" (or bigger) Tender - Engine coupling, they can be divided into as many "ways" as you want. (Would probably be too large for "N" gauge).
Far, far cheaper than the only other, similar product I have found (from a USA supplier).
While you are looking at these, browse the site and you will find a treasure-trove of goodies you will want to spend on!