Affordable Equipment Made in AMERICA Custom S.C.U.B.A regulator necklace improves upon a tool that technical divers have used for years to keep the back up regulator under the neck and chest area. This Fully adjustable, necklace is purchased by divers neck size for comfortable fit, and shall adjusted to fall on the neck and/or chest according to individual diver preference. Just send your neck size and it will be a custom fit since divers do come in many shapes and sizes and one will not fit all.