I've used these now for three years I average a pair a year (one year I had to get another set).
For the most part the deaden the outside noise to comply then the music or sound only goes to 87db, so with them pushed in properly and the music up you can still hear alarms the dull roar of the engine and things like that. I offered to let my guys try these with new replacement tips of course some like them some didn't the ones that didn't ,said it wasn't loud enough. As for replacement tips o believe 50.00 is for a case of 50 tips. I got six tips for 6.00 with shipping on amazon.
Do it better than the last Guy!