Features:

• Find ferrous (magnetic) metal such as rebar up to 4 in. (102 mm) deep
• Find non-ferrous (non-magnetic) metal such as copper pipe up to 2 in. (51 mm) deep
• Unique design allows for dual scanning positions
• Detailed instructions enclosed. Sensing depth and accuracy can vary due to moisture, content of materials, wall texture, and paint

Editor Reviews:

Product Description:
The MetalliScanner m40 metal scanner finds studs in lath and plaster walls by detecting nail patterns. Also detects metals behind nonmetallic walls.

Rating : - Great for the money
I purchased this unit to check used lumber on my jointer. So far so good.