Who Makes Harbor Freight's Stud Finders & How Well Do Users Say They Work?

Whether you're a homeowner in the suburbs or someone renting an apartment in the city, you will probably at some point be mounting things on your walls to make the place truly feel like home. This typically involves drilling into your walls to make sure things like a new television or picture frames of your loved ones are sturdily in place. In the process, you'll want to avoid punching holes into pipes or electric wiring, while also making sure to drive nails into a "stud," or board within the wall that helps make up its frame. One of the best ways to do so is to invest in a stud finder and learn how to use it. 

Harbor Freight offers three budget-friendly stud finders from Franklin Sensors: the ProSensor M10 ($14.99), ProSensor M50 ($26.99), and ProSensor M150 ($36.99). Franklin Sensors does offer several models with more complex sensors, live wire meters, and bubble levels that you can get through other online retail channels.  The ones sold at Harbor Freight, however, are among the brand's most affordable options. 

While they share a lot of the same features, they also have key differences that can help you pick out which one is best for you. In this piece, we'll compare the specifications of each of the stud finders and consider their performance and value, based on what buyers have to say about them. To fully understand how we've evaluated them, you can also skip to the end of the article for a more detailed breakdown of our methodology.

If you just need something to help you find wood and metal studs, the ProSensor M10 will most likely get the job done. Using a trio of sensors, it will flash a green light when it detects the stud center. It's important to note, however, that the M10 model can only detect a maximum depth of 1 inch. In comparison, both the ProSensor M50 and the ProSensor M150 can scan up to 1 ½ inches deep and also have the ability to detect the edges of studs for increased accuracy. These two models also flash live electrical warnings in the form of amber lights. Between the ProSensor M50 and M150 models, the main difference is that the former has five sensors, while the latter has nine.

In terms of power, the ProSensor M50 is the only one that runs on two AA batteries, while the other two use two AAA batteries. Unfortunately, none of the options are rechargeable, and the batteries need to be purchased separately. Weighing 0.45 lbs, the ProSensor M150 model is the heaviest of the bunch. However, that weight is similar to something like the iPhone 14 Pro, so it's still light enough to hold with ease. Regardless, none of the models require complicated calibration procedures, so even amateurs can use them immediately.

In general, most buyers appear to be satisfied with all three Franklin Sensors stud finder models that you can buy on Harbor Freight. Many praise them for being worth the price and easy to use. Unsurprisingly, the most popular option is the cheapest model, the ProSensor M10 Stud Finder, which more than 1,300 users gave 4.2 stars. While we think it's definitely a great budget find among Harbor Freight's home improvement tools, there have been about 100 people to give it a single-star rating, citing inconsistent results and issues with certain surfaces like tiles.

The mid-priced option, the ProSensor M50,  is somewhere in the middle when it comes to ratings, with an average of 4.5 stars granted by more than 600 people. As of September 2025, 88% of reviewers had given it at least a 4-star rating, but there were some users who still reported the tool to be inaccurate. As the most expensive of the trio, the Franklin Sensors ProSensor M150 is also the most highly rated option, boasting an impressive average rating of 4.6 stars. Plus, 93% of verified buyers say they would recommend it to others. In fact, a couple of reviewers specifically stated that they had purchased cheaper Franklin Sensors models in the past but were not as satisfied with their performance compared to the M150.

All three Franklin Sensors stud finder options from Harbor Freight share similar technology, run on batteries, and can be used without any complex calibration procedures. However, there are several important things that make the more than 100% price difference between its cheapest and most expensive model worth it. 

We considered each model's price, along with how users reviewed the items and overall performance specs to compare the different stud finders in this piece. It was important to consider the number of sensors, for example, because this can contribute to the overall effectiveness of the stud finder. Regardless, all three models are generally well-reviewed and have netted themselves at least 4 stars. If you're a professional, however, you may want to consider looking into Franklin Sensors' other products, which have more elaborate features that leave less room for error. In this case, you might consider something like the ProSensor M210, which made it on our list of the best stud finders for any job.