Technically it's a CRD (Cable Retention Device)
designed to utilize any existing port (USB, RJ11 or RJ45)
on a laptop computer as a stay or restraint to keep the very fragile AC power connector from being damaged from day to day tugging and pulling and jerking on the power cord.
Repairs to this connector as a result of the cumulative damage from day-to-day tugging and pulling can range from $100 to $250 or more if repairable.
The (Patent Pending) JerkStopper™ Cable Retention Device keeps you and others from causing costly damage to your Laptop Computer.