Stanley FMHT77407 FatMax Stud Sensor 300
- Up to 1-1/2 inch wood and metal stud detection depth
- Up to 2 inch live AC wire detection
- Up to 3 inch deep metal scan
- One Pass center-find, locates stud centers
- Backlit LCD screen, readable in low light
- 9V battery power, battery not included
- Auto-calibrating, with a marking channel
Last refreshed Sep 7, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A capable stud sensor for locating framing before drilling into drywall, with center-find and live wire warnings; plan to buy a nine-volt battery, since none ships with it.
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ASIN: B00A905Y2UCategory: Stud Finders
Overview
Sliding the Stanley FatMax Stud Sensor 300 across a wall in one pass shows the center of a stud on its backlit screen. A separate deep scan flags buried metal, live AC wiring is detected too, and a marking channel guides the pencil.
Center-find in one pass saves the back and forth of marking both stud edges, and the backlit screen stays legible in a dim closet or basement. Its wood stud reach is modest, so thicker wall build-ups may hide framing from it.
Who it's for
Weekend projects like mounting shelves, mirrors or curtain rods on drywall are its home turf. Those working through deep wall assemblies, or who want a magnetic finder with no battery, should look at other tools.
Pros and cons
- Finds stud centers in one pass
- Warns of live AC wiring
- Deep scan mode for buried metal
- Backlit LCD readable in low light
- Battery not included
- Wood detection limited to thin surfaces
- Battery life not listed
- Deep scan senses metal only
Performance notes
Readings depend on the auto-calibration step and on moving the sensor flat across the wall. Wood and metal detection works through thinner surface material, while the deep metal mode reaches further but only for metal. The marking channel lines the pencil up with the reading, which cuts error when transferring the spot to the wall.
Specifications
| Brand | Stanley |
|---|
Frequently asked questions
Can the Stanley FMHT77407 find studs behind thick plaster?
Only within its listed range: wood and metal detection through up to 1-1/2 inches of surface material. The deep metal scan reaches up to 3 inches, but that mode senses metal only.
Is the Stanley FatMax Stud Sensor 300 a magnetic stud finder?
No. It is a battery powered electronic sensor with an LCD display and auto-calibration.
How do I mark a stud with the Stanley FMHT77407?
Use the marking channel on the unit to mark out the reading. Stanley says it improves the accuracy of marked positions.
What is in the box with the Stanley FMHT77407?
One stud sensor. The single 9V battery it uses is not included.