This is the Atomic Aquatics Hose Protector (Strain Relief) for Regulator, Computer, Octo, and Gauge Features: Prevents strain and damage to hose fittings Easy to install Extends hose life The Atomic hose protector will help keep your regulator set up in its best condition possible. These protectors can be added to your hoses on either side or commonly on the side attaching to your 1st stage. These help keep the hoses from becoming damaged for being slightly bent coming off the 1st stage. It will not only extend your hose life, it also makes for a very sleek and put together look for your regulator. Inside, they are designed to fit the nut on the regulator perfectly which makes for an easy installation and a great fit.