The standard QR that campagnolo made and everyone in the world copies has threads on one end only - and a head with an offset oval hole drilled across it on the other end. The QR lever has a cam that fits into that hole, and rotating the cam moves the cap toward the wheel. If it is threaded at both ends, you have a deal like Noah posted a picture of - not bad, but not a quick release setup. The bolt end is usually fastened with a 5mm allen key. We used to call 'em slow releases, and they have been on every cross-country racing rig that I've ever owned.