10,000 of them can be handed in to Eira in Burthorpe to receive rewards, and any spares can be given to receive event mystery boxes or big event mystery boxes. If the player has any clockwork pieces left after the end of the event, the following message will be shown upon login: Clockwork pieces can also be converted directly into mystery boxes (without progressing the event) at a cost of 250 per event mystery box or 500 per big event mystery box. Clockwork pieces can be stored in the currency pouch to save bank and inventory space and can be handed in to Eira directly from there.