Fishers two box has a reputation for being the best. Goes deeper, & traces farther! Two box treasure hunters know that Fisher's Gemini-3 has a reputation for being the best there is. Designed to locate deep objects; depending on ground mineralization and target size objects may be detected as deep as 20 feet! The Gemini-3 goes deeper, traces farther and is easier to use than any other cache finder in its class. Backed by Fisher's Lifetime Warranty*.