The Garrett GTI 2500 metal detector has been one of Garrett Metal Detector's staple metal detectors for quite sometime.  Not only does it give you a better visual display output (i.e. better ability to identify targets prior to digging), it comes with some really cool attachments. 

The Garrett GTI 2500 Eagle Eye package is really two detectors in one.  This bundle can be used as a normal, hand held, sweeper or it can be converted, using "suitcase style" deep seeking coil, by attaching the Garrett Treasure Hound Coil This allows it to detect larger metal items (such as hoards, caches, or other buried treasure) several meters underground.

By attaching the Treasure Hound Coil, you are able to detect really deep.  It is not like a common detector.  You don't sweep left to right.  Rather, you hold it like a suitcase and walk in well coordinated straight lines.  This behemoth of a search coil even has the ability to pinpoint those deep targets.

The GTI has been a long lasting and very useful metal detector.  With the variety of coils, which is unsurpassed with any metal detector, it will likely be a solid choice for years to come.