Found in the Underway Dungeon with the Baronical Jester costume.
Telescope of Unveiling
Rarity Uncommon, approx 200gp.
Standard viewing range is 650ft.
There is a button hidden *?Found by Larealla,
that as 1 Action activates at a range of upto 300ft, to see past barriers less than 5ft thick,
and can see those that are invisible, or in an Ethereal plane.
The button will stay pressed down for 1 hour before it resets into it's normal telescopic mode.