Peltor TEP-100 or TEP-200. The latter has some wireless audio transmission capabilities, but not very useful for competitive shooters (requires some neck loop to be worn).
I have use these for years now. Battery lasts all day for at least 4 years before the built-in batteries deteriorate. With skull screw tips in, I find them working well enough stand-alone with an open gun outdoors.
I have several pairs of passive custom molded plugs, and found that within 2 years or so they don't fit as well as they once did. Guess I'm still growing at 30? These are even the soft silicone ones, rather than hard plastic moulded ones.