The 2Keys (every Rogue needs) (Patreon)

Wondrous Item, artifact (requires attunement)

This pair of magical keys have no apparent bit. Instead, its shank is filled with arcane runes. When you activate its effect, the runes light up and form a magic bit that can be reshaped to fit any lock. The two keys can never be apart from each other or from the creature attuned to it. If they are ever more than 20ft apart, they magically appear back in the owner's pocket.

When you attune to these magical keys, you gain proficiency in Sleight of Hand and Thieves Tools. If you already have one or more of these proficiencies, you gain expertise with that skill.

Gold Key (The key for every lock). You can use this key as thieves' tools for the purpose of opening any lock. When using this key to attempt to unlock something, you make the test with advantage. In addition, once a day, you can cast Knock without spending a spell slot. When you cast this spell using the key, for 1 minute, no sound can be created within or pass through a 20-foot-radius sphere centered on you.

Black Key (The key for every door). Once a day, as a bonus action, you can touch this key to a solid surface no more than 5ft thick. A magical door appears on that surface and remains there for 1 minute. In addition, once a day, you can use this key on any door to create a magic connection with any other door you have ever seen that is within 500ft. That creates a portal that takes you from one door to the other. The portal remains open for 1 minute or until you use the key to close it again. All creatures that pass this magical portal are concealed in a magical mantle of darkness. For 1 hour, they gain advantage on all stealth checks.