Walk through metal detector purchases?

[horseshowmom]

I'm in the process of purchasing walk-through metal detectors for school use (in the school gyms for sure and maybe other uses).

Does anybody have any positive experience with these? I'd love to have some brand suggestions. We bought these several years ago, and the school quit using them because they said they were too much trouble (went off over everything and backed the lines way up). Since we're very rural, we don't tend to have problems, but you never know of course. The new supt. wants new ones, so I would love to have some practical advice.

Thanks!