This vintage pair of AR acoustic research 5ohm tweeters is a great addition to your audio collection. These tweeters are from the S-40 speakers and have been tested and are working perfectly. The brand of these tweeters is Acoustic Research, a well-known brand in the audio industry. The model of these tweeters is S-40, and they were made in the United States. These tweeters are perfect for anyone looking to upgrade their audio system or add a vintage touch to their audio collection.