A bumper is an intermediate stage between a back cover and no case at all. It’s a frame that covers only the edges of your devices. It has all the holes for buttons and ports.
Not protected back side and front might be a little critical if you carry iPhone 7 or Samsung devices, which are certainly not cheap mobile devices.
Usually, bumpers are made of aluminium or TPU or plastic. The first type is a better option. Bumpers, made of anodized aluminium, are light as a feather but they are incredible solid. To attach such bumper to the phone you’ll have to use special screws which come in a set and provide protection against cracks or dents. TPU bumpers are more affordable, they are easy to put on and take off. They are okay for everyday basic protection, as they serve as shock-absorbers in case of a drop. Also, there are bumpers which combine two different materials. They are usually double-injection, which presents the best safety for the most popular Apple or Samsung mobile devices.
Bumpers are very widespread among smartphone users. People love for a number of reasons. First of all, they don’t add any thickness or weight to the phone, so there’s no discomfort for users. Also, they are pretty simple to install. And despite covering only the edges of your device, bumpers still provide minimum protection, absorbing shock.
In this case, though, protection can also be seen as a disadvantage. The rear side of your iPhone isn’t safe from scratches or dents. Users will have to be careful, when carrying phones in pockets with other personal items. This may be the only drawback but it’s a pretty serious one.
In general, bumpers for smartphones and tablet devices are still in a great demand. They are nice option for those, who want basic protection for their smartphones. And as we know, it’s better to have your devices at least slightly protected than not protected at all.