If we were still looking for evidence that smartphones have officially become a commodity, the line of ruggedized devices from iconic heavy equipment maker Caterpillar might just be that proof. We reviewed the Cat S40 Android phone to see if it offers a unique take on a rough and tough device or if it's just another phone with an unlikely brand name slapped on the back.

Caterpillar is a name that's synonymous with construction, big projects and big gear, so it's not surprising that the major selling points of the S40 include its ability to stand up to the kind of conditions you might encounter on the field or the job site. This medium-sized phone is rated to be water, dust and drop-proof with a 4.7-inch Gorilla Glass 4 display designed to work with gloved or wet fingers.

It's rated IP68, which means it should stand up to high-pressure jets of water and to accidental submersion. Bullitt Group, which manufactures the S40 for Caterpillar, goes a bit further to claim that it will resist submersion for a full hour in up to a meter of water. It is also rated to withstand drops from up to 6 feet (1.8 meters). It also fulfills the military standard for being resistant to salt, dust, humidity, vibration, shocks and solar radiation.

We had to keep our review unit in working order so we weren't able to really torture it, but it did stand up just fine to some moderately rough drops, serious splashes, submersions and attempts to scratch the screen. We also made sure to hand it over to a few kids for a while to really put it to the test, and it came away in one piece from those encounters.

Like many other affordable ruggedized phones, including Kyocera models like the Brigadier, the S40 seems to trade power and performance for toughness. Its Snapdragon 210 processor, 1 GB of RAM and 540 x 960 display don't exactly impress and can get bogged down by more memory-hungry apps.

So if you're a power smartphone user looking to push a phone to its limits through gaming, serious multitasking or as a heavy media consumption device, you can probably stop here and look elsewhere, but if you're still intrigued by a phone you can take anywhere to keep in touch, let's consider what else we like about this phone.

First there's the bright screen that's designed to work well even in direct sunlight outdoors. We found it workable even on bright days here in the high desert from most angles.

The 3,000 mAh battery is also above average, promising up to 18 hours of talk-time and 39 days of standby. While we weren't able to connect this unlocked GSM-only phone to a compatible LTE network to really test out the battery drain, it lasted several days connected only to WiFi without a SIM card inserted. It also lasted several hours on our looping video test, but without LTE on, it's hard to glean much from that.

The form factor, while about as bulky as other rugged phones, offers a nice textured back and rubber, angled corners for a better grip. Three physical navigation buttons across the bottom of the screen and a customizable extra side button are standard for phones in this category and work fine. It feels substantial in the hand, which is better for working in the field, perhaps with gloves, than trendy super-thin flagship phones.

The waterproof covers for the SIM, SD card slot, USB, and headphone jack are among the sturdier options available but also some of the easiest to access we've seen on this type of phone. We also like the waterproofing warning sensors that warn you when the covers aren't fully closed.

The Android 5.1 Lollipop OS the S40 ships with is pretty close to stock with no real bloatware to speak of, save for a CAT apps storefront, a file manager and a few other utilities, including SwiftKey.

Every other feature of the phone is pretty marginal or below average. The speaker is just okay, and not as loud as competing phones from the likes of Kyocera or Sonim. The lack of sharpness to the 234 pixels-per-inch display is also detectable, and becomes a minor irritant once you notice it, especially if you're switching between the S40 and crisper displays during the day.

The 8 megapixel rear and 2 MP selfie cameras are also quite average and basic. No fancy image stabilization or laser autofocus here, but for simple photos it should do just fine, although a processing lag due to the under-powered hardware is sometimes an issue.

In the end, this phone does feel a little bit like a commodity item in new packaging. But, the price of the CAT S40 is right at US$399 if you value toughness over power, especially since comparable phones from competitors like Kyocera are either growing stale or hard to find unlocked. However, if you want both resilience and performance, you may want to consider spending a little more on something like the Samsung Galaxy S6 Active.

Product page: CatPhones

Buy it now: Amazon

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