Ideal for coin shooting in trashy areas Perfect for gold prospecting Great for use in small, tight areas Is Waterproof and can be used under water Can be used with all Bounty Hunter models While a standard coil is great for finding large objects that are deeply buried, the 4 inch coil has a narrower field of detection enabling your detector to seperate objects more efficiently. The 4 inch coil's shallower detection area makes it ideal for prospecting in difficult, high metal areas since it allows you to more easily discriminate valuable objects from refuse. In addition to allowing the precise pinpointing of objects, a smaller coil lets you probe tight spots such as corners and crevices.