Save your money. All these supposed cures you find online, are unfortunately scams. Sorry. If you're new to "T" and this site, you will find a lot of knowledge within. check out all the forums and you can also search with key words, like "RingZen" and see others opinions.
This is a sham and no where near worth $33. The main ingredients are just some citrus vitamins (most likely C and B vitamins which are not proven to help T), garlic (not proven to help T), low grade Magnesium Oxide (the cheapest type and worst absorption rate of any Magnesium) and low quality Gingko which does not work. You could buy them separately for much less.
Many of the positive reviews are people who received the product free for their honest review and frankly doubt they had T to begin with.
I saw an audiologist yesterday who specializes in T, as I am new to this as well. She told me that all the anti ear ringing meds out there and all the supplements out there purported to help with Tinnitus have been disproved in blind studies. She also said salt, caffeine and alcohol are also all fine in moderation and studies have shown that they have no impact on Tinnitus. I decide to stay caffeine free to better manage the anxiety I am experiencing around this but was glad I could stop spending my money on stuff that does not work. I am putting my money into a nice sound pillow to help me sleep.