USA 
S50 Edge-Detect 3/4" Stud Finder
Product Description
- This stud finder detects wood and metal studs up to 3/4" beneath material
- Auto-calibrating AC detection
- Visual LED indicators on face of stud sensor for easy readability
- Accuracy up to 1/8" for wood and 1/4" for metal
- Use for mounting TVs hanging shelves and pictures or even wall demo
- Includes 9V battery