This brand is well reviewed on Amazon:
https://www.amazon.com/gp/product/B0..._al_bw_c_x_4_w
Various wattages available.
Remember that the number of 12 volt DC amps used to supply an inverter is about 10% of the watts 120 volt AC output, so 100 AC out watts = 10 amps DC input, etc.
Example:
TV uses 120 watts, inverter draws 12 amps. Your RV battery is a group 24 with 75 amp.hours capacity. You do not want to discahrge the battery to less than 50% of its amp. hr. capacity, so you have a useable 38 Amp. Hours. That would be just a bit over 3 hours of TV use from a fully charged battery.