We found one really great review we wanted to share here:
Simple no frills metal detector that is tuned for saltwater. I currently have two detectors I use, a third one(ACE 350) I gave to my son to use. Since I bought this CZ-21, I have really enjoyed beach hunting!! My other machine is a Garrett AT Pro that I bought with gift cards from my sister for my birthday. The AT Pro is decent for the beach and I can’t knock it too much. After all, I found my first gold ring with it. But, the CZ 21 outshines it at every aspect. This detector is a Dual frequency VLF machine, thus it runs really stable in saltwater. My AT Pro is a chatty thing in the water. Yes, those who are obsessed with the AT Pro tweak it to quiet it down, but that reduces the depth as the AT Pro is a single frequency VLF machine. I have found a gold, silver and tungsten ring with my Fisher CZ 21. I have also recovered over 20 fishing sinkers as well. For those who hunt the surf seriously, you know you have to hit sinkers to find the gold. The CZ 21 is waterproof to 250 feet and is used by divers. The only downside to the Fisher is that the coil is hard wired, along with the headphones. There is no swapping out coils without sending the unit back to Fisher. For me, it is not a big deal at all. I like my 8 inch coil as is. The unit itself is pretty hefty, but I chest mount mine. That way, I am swinging the coil only!! It is light weight and I can swing it for hours without feeling tired.
The detector has three tones, low, medium and high. No fancy LED readout or numbers to worry about. Just turn the knobs and go. I love listening for the tones as it lets me know what is underneath the coil. With this unit, you can also run auto tone that picks up everything. To ground balance, you turn the knob and do it the old fashioned way, by hand. There is no auto ground balance feature, you, the user are in control. IF you want a well built machine with no frills, and want to find gold or silver jewelry, along with coins, get this machine.