I bet it is a standard hose. I've replaced the two shower hoses in our LTV Free Spirit with hoses purchased at Home Depot. Take your old hose to the store to insure compatibility.
At the same time, I added push-button valves to instantly stop flow to save water when it's time to rinse. For the record, most of our showering using the RV setup is of the dog, using the outside shower. The push-button valve is especially useful then.
This is a great head with a good length hose.
Camco 43714 Shower Head Kit with On/Off Switch and 60" Flexible Shower Hose (White) https://www.amazon.com/dp/B000OAG63G/ref=cm_sw_r_cp_apa_i_D4XZCbAKEXG3S
jooe Handheld Shower Head with ON/OFF Pause Switch, New High Pressure Water-Saving Powerful Spray for Angle-Adjustable, Square, Chrome Finish, Easy In. Got this on Amazon. The best. Easy to shut off flow when your hands are soapy.