Do not get the cheapest one out beware they are cheap for a reason. We have been out of our stick built since Jan 1st when our Cheap dehumidifier (2 yrs old) caught fire and smoke and sooted the whole house we are down to studded walls. Look at the Consumers reports to find a good reliable one.
We had 3 or 4 over the years. They all did the job but the best one for me was one that was flat on top. Put it right next to my chair and the flat top worked perfect for "end table". Also get a couple gauges so you can see if its doing its job through out your rv, not just close it. I use 3 of these in different spots. They are for cigars storage boxes but work great to check humidity. https://www.walmart.com/ip/Xikar-Digital-Round-Hygrometer/713812767?wmlspartner=wlpa&selectedSellerI...
2003 Majestic 23P... Northwest travel machine 2013 Arctic Fox 25W... Wife "doll house" for longer snowbird trips 2001 "The Mighty Dodge"... tow vehicle for "doll house"
Search online for ratings and pick the biggest one with the highest rating. You wont go wrong. Pump? Naw, dont need one. Set it on a table with the hise sticking out a window. Done!