Acs pro series hearing protecton summary the acs pro series hearing protection ear plugs are the pinacle of earplug technology allowing you to hear what you need to hear at a safe volume in comfort features custom made for your ears 40 shore silicone with steritouch various colour options standard clear a revolution in custom hearing protection the pro 15 by acs provides more subtle attenuation thats perfect for use in acoustic or orchestral environments sloping up in the higher frequencies fo