Weights Make sure they are true and stamped.
Swivels Make sure they are of good quality and they will last years and you can rest assured your bird is safe when tethered. Telemetry For tracking lost birds. Buy from a good supplier as some systems have no back-up if damaged or needing spare parts. They must be made from good quality leather and kept well greased. They can be bought ready made or buy the leather and make your own.