Roswell&';s new 3 Inch Universal Clamp is designed to work with up to 3-inch diameter tower tubing and comes standard with 2.375-inch & 3-inch plastic inserts. If you&';ve been held back putting Roswell Tower Speakers on your tower with larger tubing, the wait is finally over! EACH SOLD SEPARATLY Includes: 2.375", and 3" plastic inserts Compatible with most Roswell product Saltwater friendly