What do I have to bring at least?

Swimming:
Swimmin trunks, swimsuit, goggles if possible, wetsuit for swimming if necassary (max. 5 mm thickness). The wetsuit will be prohibited if the water termerature reaches 23°C or higher, because it is used primary as a functional protection against the cold water and not as a flotation device.

Cycling:
Bike of any kind, it only needs to be roadworthy (all screws tightened, set tax rate, tires and spokes tight, both brakes fully functioning, lighting installation is not required); the traffic safety will be checked by independent referees before the start. If the bike is unsafe, you can repair the defects at the mechanic booth. If a quick fix for whatever reason is not possible, you will be excluded from the race. Furthermore: appropriate footwear and clothing, suitable and approved helmet (no start without a helmet!), drink bottle filled with water or sports drink, sunglasses if necessary (useful for eye protection).

Running:
Appropriate footwear and clothing, head protection against solar radiation if necessary.

This and that:
For a quick change, a purchase of a number rubber band pays off. This way the number can quickly be moved from the back (for the cycling) to the front (for the running). Alternative, a normal rubber band will work as well.