I.down1[美 daʊn, 英 daʊn]副down often appears as the second element of certain verb structures in English (back down, clamp down, tone down, etc). For translations, see the relevant verb entry (back, clamp, tone, etc).
It's shockproof to 2.6 feet (0.79 meters), and waterproof to depths of 9.8 feet (2.98 meters) but some concessions have been made to keep the price down.
However, recent developments in open-source hardware designs, at least one of which is commercially available for purchase, have brought the price down significantly.