Keeping Up with Shoulder Prehab While Traveling?

Title says it all, I typically use dumbbells per Eric Horst's recommendations for shoulder maintenance but obviously won't have easy access to those while on climbing trips. Any tips on what you guys use on longer climbing trips?

Edit: I'm an idiot and forgot about exercise bands. Eric Horst does mention that in his opinion exercise bands are only useful for warming up or rehab, but building strength in the stabilizing muscles should be done with dumbbells. But seeing as this is maintenance on a trip I'll definitely bring bands with me.