This item is the SHORT yoke that comes standard with the Hollis Prism 2 Rebreather If you are large or tall or large AND tall, you need the LONG yoke If your Hollis Prism 2 Rebreather Counterlungs are too high on your chest or on you cheeks the LONG (not this item) will move them down your chest. You may need custom length hoses as well, Please call one of our Prism 2 Instructors to answer your questions. 813 887 5712