Etymotic Research® ER-25 Single Filter for Musicians' EarplugsTM (Clear)

you music Pro adaptive electronic earplugs offer the performance of the ER 9 and the ER 15 pest of musicians earplugs combined in a single device music Pro tear plugs allow natural hearing when no noise is present an automatic protection when safe levels are exceeded the following instructions make operating the music pro quite simple step one remove the batteries from the dial pack remove the brown sticker from each battery before inserting it note that the battery has tiny holes on the flat side air enters these holes and activates the battery step to swing open the battery door step3 install the batteries place the battery in the door and closed compartment the battery only fits one way if the battery is inserted incorrectly the door will not close step four select an ear tip if the standard ear tips that come on the music pro your plugs does not fit select another the ear tip that i