I have always hated fumbling for the wall outlet below my 335 dinette. Searched for a solution for quite a while and finally found this inexpensive unit on Amazon
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1. Cup holders are really not that useful and this one fits only after filing maybe 0.050" using a rat tail file.
Finally...nice access to 120 volt and USB charging in the dinette. Now if I can find a use for the other cup holder I will be all set!