Nozzle holders, protectors, guards and cleaning pins. A nozzle holder lets you change nozzles without tools and keeps the orifice square to the lance. A protector takes the knock when the lance is dropped, which is what usually kills a nozzle.

Holders are sized by thread and by the nozzle they accept, so check both against what you have. Rubber protectors are cheap insurance on any lance that lives in a ute. Cleaning pins are the right tool for a partly blocked orifice - a wire or a nail will open out the hole and change the fan pattern permanently, and a nozzle that sprays crooked is scrap. Keep a pin in the kit and a spare nozzle on the shelf.