The four letters in the middle are the Hebrew letters for YHWH, or one of the names of God. These four letters are called the tetragrammaton, which is also the name of a protection symbol which includes the aforementioned four letters. This might be a variation of a tetragrammaton symbol.more »
This is a tetragrammaton! It combines Christian, Jewish, pagan, and even some alchemic (although alchemy is not a religion) symbols to create what is considered a powerful protection symbol.
Looks like it could be the elder futhark rune Sowilo, representing confidence and empowerment. One alone is fine, but if you see two of them side by side tattooed on someone, they're probably a neo-nazi.