I have read many review on a variety of surge protectors and brands for RVs, and Progressive Industries seems to come out on top each time (or at least in the top 3). It is on the bulky side (which is not an issue), but not too heavy. The instructions are clear easy to follow and provides convenient error codes on the side of the device. It is built for handling the weather and has a good weatherproof *cover.

*note: the latest clear weatherproof covers should be even deeper to accommodate some newer RV handles. I have a 2021 Leisure travel Wonder power cord, which is 3" tall - too tall for even the latest covers (about 1/2" more space needed). I had to use their extra kit (for another model) to modify my housing to have room for my plug handle with the clear cover down. I used 3M double sided tape to attach to the original housing edge, and cutting out part of the bottom to the kit piece. It looks a bit bulkier now, but at least the plug handle fits. (see pics)

It comes with a security collar attached to prevent theft at parks. The fact it protects against low and high voltage, reverse polarity, open neutral, open ground, AC frequency protection, and accidental 240V protection, gives one peace of mind when plugging in.

My RV actually came with a built in surge EMS protector from Progressive Industries, but is not easy to access to see the display when hooking up at a site. I don't really require this external SP, but I just prefer to have the redundancy, and I can easily monitor the status if anything happens. I could also have just used a Progressive Industries tester for the pole before hooking up. Less expensive, but no redundancy. It's all preference :).

Also, their customer service is amazing and will do all they can to address any questions or issues.

I'll start by saying I have limited experience. I've only used this one time on my first camping trip after purchasing my first travel trailer. Here is my experience and thoughts. It arrived on time and worked exactly as described. Although I did not have any electrical issues for the safety features to kick in, I believe they would if the situation warranted it since everything else operated as expected. When I plugged it in and applied power to it, I received all the indications the users manual stated I would received for a good power source. I am not an electrician, but I can follow the users manual (which is easy to understand) to see that it was working properly and I had good power. I really like that the display cycles thru volts, amps, frequency (i think it did frequency but I'm not 100% sure), and the error code (if any). The Amps indication helped me figure out which loads I could run together so I didn't overload the breaker and lose power. Basically to use the microwave I have to temporarily turn off the AC/Heat. My first night at the camp ground it was raining heavily and the plastic cover on the front kept out rain water. I did not lock it, but it has a metal tab on it near the top where you can lock it using a cable or chain if desired. I probably will use that in the future. Since this is my first RV surge protector I bought I don't know if the price was good or not. All in all I think it was a good purchase. I am happy with my EMS-PT30X and feel confident that my travel trailer is electrically protected. I'll update as we use it more.

Update#1: I've used this now at 8 campgrounds across 7 states. It's worked well every time. When I hook it up I also install a metal chain with a couple pad locks to deter theft. Easy peasy. So far so good! I recommend it.

Update#2: Had my first error code. I overloaded the breaker by running the microwave while other things were running. My fault. It tripped power off to the RV, then shortly restored power automatically. It gave me the PE4 error code on the unit which basically meant I overloaded it (had to search on the internet for the error code). The error code (most recent if you have multiple) stays in the rotation of information that cycles thru on the display. So it did what was advertised! Yay! I'm still happy with my purchase.

Update#3 Three years later and it's still working great. I only use it at the campgrounds. At home I know my powers good so I keep it stored in the camper.

Worked how it was supposed to. Now we have not had any issue with electrical yet, we hope to never have to use the safety features. If we do need to it will save a lot of money as opposed to replacing RV appliances etc. Came on time a little larger than we thought but happy with purchase.

We purchased this surge protector for our motorhome for its safety features and have been very happy with how it works. We use it for 50amp and it clearly indicates when everything is working correctly. If there are issues, it will cut power before allowing injury to the motorhome inverter. It will also put up codes if there are any issues on the power side.
We have used it in freezing temperatures and rain and have noticed zero leakage or issues due to the temperatures. We live in a very hot climate and have camped with it in 104+ degree temperatures with no problems.
It holds tight to the outlet allowing no slippage. You can purchase a lock to keep people form stealing this surge protector, however we have not used this feature yet.
We have been very happy with this product and do recommend it to others.

I like the various readouts, and safety features. After several months, the surge protector started giving erroneous readings, so I contacted Progressive Industries. After hearing my description of the problem, they asked me to send them a picture of the plug to show there was not an issue with the electrical connection at the source. They determined the circuit board was "fried" and promptly sent me a new replacement. They told me to throw the old one away. Since I was curious about the surge protector, I took it apart. It turns out there was a leak around where the plug entered the cover that allowed water to enter. So I dried out the circuit board, and reassembled it. It has been working fine ever since.
TIP: Tighten the nut that compresses the gasket that seals the cord where it enters the box. It seems quality control was the issue. The actual quality of the surge protector is excellent.