Beard trimmer help!

[capabilitieso]

FIL's care home have asked me to send in a beard trimmer. He has an electric razor already. He has Parkinson's and is quite stopped now so some of the carers struggle to shave under his chin and then it gets left.
I have NO knowledge of these things. DS1 wet shaves, DS2 is a hairy thing but at only 15 he's managing with some all-in-one jobby at the moment.
I want something not too expensive, rechargeable, and easy to operate and clean.
There are 3 million to choose from.
Help!

[DaneShayd]

I think you may want a shaver rather than a beard trimmer as such.

[JasonByrne]

I got a babyliss hair trimmer for my dad and it's been great—lightweight, simple to use, and doesn’t need perfect coordination. The guard clicks in easily and it's not too noisy, which helps keep him calm. I usually set it up for him and just let him do the trimming himself with a mirror. Battery lasts long enough that we don’t have to charge it every single time.