Argaz's Circus Sash

This brightly colored sash flies impressively behind its
wearer’s tumbling and springing.
Add your Proficiency Bonus to Acrobatics checks. If you
are already proficient in Acrobatics, add your Proficiency
Bonus a second time. As a Bonus action, you can roll an
Acrobatics check DC 20 to ignore Difficult Terrain and
move along vertical surfaces as if they are horizontal until
the end of turn.

Source: Atma's Arsenal, Pg. 9

Notes: Buff, Belt