Same as the excalibur headphones, just gut and trim to fit inside of the Peltors...they will be the best set of headphone you have ever had for the beach...
i had the same problem on mine just call whites and they will replace them free, just put some silicone on them when pushing the new one in, it's a little hard but it can be done. Harold Help with Repair of White's PI Pro U/W headphones