The Minelab 6 inch Smart Coil is the first of it's kind for the FBS-2 CTX 3030........ Application The waterproof 6-inch round Double-D coil is very sensitive to small targets, and perfect for finding treasure in high trash areas. It is also ideal for manoeuvring in difficult terrain. A protective skidplate is included. Water Protection Waterproof: Submersible to 3 meters. Ideal for wading at the beach, or detecting in streams.