Mummified Bat

This talisman is the magically treated corpse of a tiny bat bound in papyrus. When activated, the affixed weapon detects vibrations around you and guides your perception. For 1 minute, you don't need to succeed at a flat check to target concealed creatures. You're not off-guard to creatures that are hidden from you (unless you're off-guard to them for reasons other than the hidden condition), and you need only a successful DC 5 flat check to target a hidden creature. While you're adjacent to an undetected creature of your level or lower, it's instead only hidden from you.

If you have the Blind-Fight feat, you gain imprecise echolocation with a range of 30 feet for 1 minute. This makes creatures that would be undetected by you because you can't see them hidden instead.