What do I get at registration, and what must I wear in the race?

From the official aQuellé Midmar Mile FAQs, each swimmer's race pack contains:

• A timing chip on a Velcro strap, worn on the ankle with the number facing outwards. No timing chip at the start means no swim.
• A barcoded tag with a safety pin, pinned to the inside of your costume. It's a back-up for timing (and for finish position in Events 5-8).
• An official swim cap in the colour of your allocated start batch. The official cap must be worn; no other cap is allowed.