The Mark-1 Metal Detector was designed and manufactured by Bill Hays of Hays Electronics in 1962, using an 8-inch search loop, the first of that size on the market at that time. The standard size in 1962 was the 11-inch loop.

In 1963 Hays Electronics introduced the first 5.5-inch loop on the the mark-2 Metal Detector. It was very sensitive for small objects and it had a depth range of 30 inches on large objects.

Today about 70% of all mark-1 and mark-2 metal detectors are bought by utility companies. Most utility companies want an all-metal detector and have no need for a discrimination detector.

In sales the Mark-1 and Mark-2 metal detectors have sold over 76,987 machines as of December 23, 2005.

Two detector field reports have been written on the Mark-1 and Mark-2 metal detectors, one by Western & Eastern Treasurs in 1979 and one by Lost Treasure in January 1999 by Reg Sniff. Go to www.losttreasure.com, click on Field Tests and click on Hays Electronics. You'll see the test results for the Mark-2 there..