Brand New Genuine Adam Tweeter for all S Series including S7MK- but not for S1A or S7MK2. 4 ohms, 40 uH. There are five tweeter options. To determine which tweeter you need, remove the tweeter screws and look on the tweeter magnet to determine if you need the 20 uH, 30 uH, 40 uH, 50 uH or 60 uH version. This one is the 40 uH.