As a previous poster noted, the AN/PSS-14 is the standard issue. For military use one of the considerations is size and weight. There are a number of units that are used worldwide for landmine detection in military and humanitarian demining work. Look up the EUDEM metal detector comparison report on Google. The most common aspects of the lanmine metal detectors is light weight, ground balancing, minimal user adjustability and variable sensitivity. I have used the Minelabs F3 and the Foerster MINEX 2FD 4.500. Both are between $2K and $3K. The Minelabs is time domain using the Candy variable period patent and the Foerster is frequency domain using two frequencies. Some other similarities are the ways that they can be carried. Both are collapseable and height adjustable. They can be used standing, kneeling or lying prone on the ground while using a non-ferrous mine probe in the other hand. There are no displays or adjustments other than on/off and volume. The Minelabs has two interchangeable sensitivity packages, one is red and the other is black and it is quite simple for a supervisor to see which package is in use from behind the operator. I have a bit of experience in this area since I am a geophysicist who looks for landmines and UXO and I have been to Iraq. Feel free to ask other questions.