While attuned to the Ring of Attunement, you gain another attunement slot.

Hey! What's with the little "LK's" thing?

I'm so glad you asked! To keep my homebrew creations separate from official material in my collections, I mark everything I mark with "LK's," which keeps it sorted separate from everything else and lets everyone I'm playing with know that this isn't RAW material, especially if I'm sharing for a campaign I'm playing in. This is something I'm slowly implementing to my already published homebrew on the site as well, giving everyone who uses my content the same heads-up. It also marks this as something I've made by attaching my online initials to the content.

Notes: Set: Attunement Slots, creature who is not an artificer.