Is a stud finder treated as a tool with size limits?

No — it has no blade or cutting function, so the 7-inch hand-tool length rule doesn't apply. It's an ordinary small electronic device.

Stud Finder

Stud finders are allowed in carry-on and checked bags without restriction.

Carry-on

Allowed

Checked

Allowed

Allowed. A stud finder is a small electronic sensing device with no blade — it's screened like any other small gadget.

Allowed. No restriction in checked baggage.

Is a stud finder treated as a tool with size limits?: No — it has no blade or cutting function, so the 7-inch hand-tool length rule doesn't apply. It's an ordinary small electronic device.