The Joyhub Carrying Case for Oculus Quest is a no-frills hard case, with just enough room for your headset, controllers, and cables or batteries.
The Quest's controllers are great but also a bit too small and slippery, and sometimes the battery covers slip off! AMVR think they have a solution.
The Mamut Touch Grips may appear expensive for what they do, but their comfort and ease overshadow its reasonably minimal cost.
The AMVR Beat Saber Handles are designed to give you a better grip for when you're playing Beat Saber, but are they worth buying? Can you keep them on?