Slip Ring with Flange - 22mm diameter, 6 wires, max 240V @ 2A : ID 736 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Taidacent Hollow Slip Ring Rotary Electrical Contact 2/4/6/12 Wires Collector Ring Conductive Electric Motor Slip Ring Rotating Connector (6 Wires 10A Inner Hole 12.7mm OD 54mm) - Amazon.com
Miniature Slip Ring - 12mm diameter, 12 wires, max 240V @ 2A : ID 1195 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits