SRD:Lantern of Revealing

Lantern of Revealing: This lantern operates as a normal hooded lantern. While it is lit, it also reveals all invisible creatures and objects within 25 feet of it, just like the spell invisibility purge.

Faint evocation; CL 5th; Craft Wondrous Item, invisibility purge; Price 30,000 gp;Weight 2 lb.