The white one from Harbor Freight is junk, . . . plain and simple, . . . don't waste your cash.
The one I have that works is a Chamberlain from Northern Tool Co. It was around $65 when I bought it a couple years ago.
Upside, . . . reliable, . . . period. Coon, cat, dog, etc won't set it off, . . . but a small human (maybe a large dog) or a white tail deer
will make it go.
It also has a relay built in that can be wired to something else if you wish, an alarm, a light, a dialer, . . .
Downside, . . . uses AA batteries, . . . 4 each time, . . . lasts between 70 and 90 days. If a spider or other bug crosses the sensor at the sensing unit, . . . it will go off.
I re-wired mine using a length of PVC tubing, . . . 2 caps, . . . and 4 D cell batteries, . . .
It's good for up to a couple hundred yards (buddy has one on his 1/2 mile drive way), . . . the fan is about 60 degrees in all directions, . . . and will detect out to about 30 yards or so.
I like mine, . . . would recommend it to anyone needing one. It's the green one in their catalog.
May God bless,
Dwight