If you're a man with a beard like my husband is, you should trim your beard regularly unless you want to look like Grizzly Adams or the members of ZZ Top. I like his beard but I don't like it looking unkempt. A beard trimmer is just a small version of hair clippers, usually it's rechargeable for ease of use. It should give several trims from a single charge. You can use a comb and an electric razor, which is what my husband once did, but he said that the beard trimmer was much easier. The comb was ok, if you like your beard short. He likes the beard and mustache trimmer that has the dial length adjustment. Basically you turn a ring around the trimmer and it raises and lowers the guard to adjust the length. That's different then barber hair clippers that have removable guards, you put one on that's the length you want. They're standard so you can go get your hair cut and say cut it with a 2 on the sides. The best beard trimmer is probably up for debate, different men have different things they like, my husband likes the dial adjustment, you might not. Pretty much all of these are rechargeable, some of them can be plugged in to the wall, if you like an electric beard trimmer. You can also get them with a kit that has a nose hair trimmer or you can get those separately.
There's Even Videos on How to Trim Your Beard
Remington Beard Trimmer MB-300
Many years ago Norelco beard trimmers were it. They had the precise height adjusting ring and an on and off switch. Simple and easy to use, over the years manufacturers would add new bells and whistles to their trimmers but they couldn't come up with the simplicity of the Norelco trimmer. The only problem with it was poor battery life. They even had those commercials I remember as a kid with Santa Clause riding through the snow in the electric shaver. Anyway this Remington trimmer has the precise height adjustment ring of the old Norelco, but they've solved the battery problem, most reviews mention how good the battery life is. Although it's Ni-Cad, it lasts for a long time. The Remington also has a curved handle making it easy to hold. It's not waterproof, but it does have a little pop up trimmer for getting into those hard to reach areas under the chin.
Wahl Beard Trimmer
Wahl has been making professional hair clippers for years, and is a highly used clipper among professionals. The Groomsman carries on that tradition of quality in a beard trimmer. It's got carbon steel blades that stay sharp and cut through hair easily. It also has a six-position regulator that attaches to the trimmer’s head so you can accurately trim and taper your beard or mustache. It also has a can trim from long hair (for shaving off your beard) to short for that daily stubble. The regulator will remember the last set height until you change it. Like the Remington it has a curved handle, but unlike the Remington. The Groomsman can operate plugged in or with it's battery. It comes with mustache attachment, close trimmers, and jaw line blender.
Norelco Beard Trimmer
The Norelco has 3 models in the top 5 selling models on Amazon. The reviewers all seem to love it. The top model is the Phillips Norelco T980 Turbo vacuum trimmer. It's got the curved handle, the 6 position adjustment and the mini beard attachments that the the others have. It's got a rechargeable battery too. What sets it apart is a built in vacuum to catch the hair as you trim and self sharpening blades. It's got a clear compartment so that you can see when it needs to be emptied. My husband has the basic model and has been using it for years.
Conair Beard Trimmer
I'm more familiar with the hair dryers that Conair makes, but they do make products for men too. The only real complaint about the Conair is that people have a hard time getting all the accessories into the base. It has the jawline combs and mustache attachments that all the others do, people don't have any problem with the way it works, just that it has so many attachments.
Panasonic Beard Trimmer
The Panasonic ER2403K differs in comparison to the other beard trimmers in that it doesn't use rechargeable batteries, it just uses AA batteries. Another thing is that it's waterproof so you can take it into the shower, and rinse it out when you're done. It's pretty much got the pop up adjuster instead of a ring, but the ideas the same, it's also got the standard mustache accessories.