A kit like the # HSE7K-T1 is designed to fit 7k axles and has a bolt pattern of 8 on 6-1/2. Based on the available information for your 2021 Jayco Eagle HT 280RSOK it either has 5,200 lb or 6,000 lb axles and a 6 on 5-1/2 bolt pattern. I recommend verifying your axle capacity to be sure. Based on this information I recommend the following:
-Kodiak Disc Brake Kit - 12" Hub/Rotor - 6 on 5-1/2 - Dacromet/KodaGuard - 5,200 to 6,000 lbs # K2HR526DKG
-Bearing Kit for Trailer Brakes with 12"... view full answer...