I've used several different two-box depth multiplier units made by various different manufacturers. This is my favorite because it is actually an attachment that is placed onto a traditional hobby metal detector, as a typical small search coil would be placed. This allows the hobby metal detector, in this case the Garrett Grand Master Hunter series(CX included)to be converted into an ultra deep seeking two-box unit. This device can find gallon sized metal object at five to six feet and larger metal items down to twenty feet or more. Smaller metal items are ignored, so you don't waste your time digging up trash items.
Pros: Lightweight and ignores smaller metal trash items.
Cons: Lage and bulky, but not too much.
This review was written in the old system and had content requirements that are different than reviews written today.