Was here with the with the 7.5 and Hi-Q coils , it leaves tomorrow,, absolutely no comparison to the big box TDI ,, and the HI-Q isn’t any better at air tests than the 7.5 coil,, Whites says it’s for relics as well as gold (HI-Q) maybe gold,, not relics having pursued relics for the past 35 years this combo isn’t it ,, I’ll stick with the big box and the standard spider coil,,, or use my other pulse the M/L GPX5000 ,, and as someone else had written ,, we shouldn’t have to buy or make higher voltage batteries to gain depth ,, don’t get me wrong I love my Whites detectors owning1, Big Box TDI ,, 2 , 6000 xl 1, Blue&Gray, 1,MX Sport ,, and 1 Eagle in Brand New mint condition too pretty to use ,, this package is advertised as a gold and relic detector / that HI - Q isn’t for relics of much depth before it taps out