Accessories
Everything that supports the main gear. Pumps, leashes, bags, board accessories, sunglasses, caps and the assorted small parts that make sessions run smoothly.
A few things are worth having before you need them: a spare set of flying lines, a repair kit for canopy tears, valve adapters for your pump, and a decent gear bag so the sand stays out of your car. None of it is exciting to buy, and all of it saves a session at some point.
If you are looking for a specific replacement part rather than an accessory, check kite spare parts.