LSA, ISOLATOR COUPLING, SOLID
This is a direct factory replacement for the original spring loaded coupler (also called an Isolator) in your 2009-2015 LS9 or LSA Engine. This part is made by EATON, and is a recommended upgrade over the spring-loaded coupler originally used in the LSA supercharger.
The supercharger coupler mates the front drive cover (also called the nose drive) to the gears that spin the supercharger rotors. It isolates the gears and rotors from vibrations and shocks from throttle load that would otherwise chew up the supercharger gears or damage the rotors.
If your coupler is failing, it will sound like there are rocks rattling around in your supercharger at idle, but the noise will soften up at speed. Replace worn couplers as soon as possible, before they start to damage the supercharger internals.