A ring of X-ray vision empowers its possessor with the ability to see into and/or through substances which are impenetrable to normal sight.

Vision range is 20’, with the viewer seeing as if if were
normal light due to expanded vision capability. X-ray vision will penetrate
20’ of cloth, wood, or similar animal or vegetable materiol, up to 10 ’ of
stone or 10 inches of many metals:
 
 

Substance  Scanned	Thickness Penetrated  per Round of X-Raying	Maximum Thickness
Animal matter	4'	20'
Vegetable matter	2.5'	20'
Stone	1'	20'
Iron, Steel, etc.	1 inch	20'
Lead, Gold, Platinum	nil	nil

It is possible to scan 100 square feet of area during 1 round; thus during 1
turn the wearer of the ring could scan a full area of stone 10' wide, 10'
high and 10 ’ thick, or 100’ wide, 10’ high, and 1’ thick.
Secret compartments, drawers, recesses, and doors are 90% likely to be located by X-ray vision scanning.
Even though this ring enables its wearer to scan secret doors, traps, hidden items, and the like, it also limits his or her use of the power,

<Constitution Drain!> for it drains 1 point of constitution if used more frequently than
once every 6 turns. If it is used 3 turns in 1 hour the user loses 2 points from
his or her total constitution score, 3 if used 4 turns, etc. Constitution loss is
recovered at the rate of 2 points per day of rest. Constitution of 2 means
the wearer is exhausted and must rest immediately. No activity, not even
walking, can be performed until constitution of 3 or better is restored.