I use Peltor SportTac electronics with the HY80 gel replacement cups, these improve the rating of the muffs and make them more comfortable.
I also have molded ear plugs which I will use with the peltors when ROing the open shooters in IPSC to add extra protection.
One interesting thing I was told is that it is important to protect behind the ear to prevent hearing damage as well, so a pair of muffs that fit well are important
Steven Butcher