●10" x 2.25"electric trailer brake assembly (left & right side), fit most 3500lbs - 4000lbs trailer axle; 4-hole mount w/mounting bolt ●Fits the wheel bolt pattern 4 lug,fits spline size #84 steel drum; center hole diameter: 3" ; bolt circle diameter: 4" ●Replace 023-026-00 and 023-027-00;77-10-2;23-105, 23-106,296649;replace Dexter Lippert Al-Ko,etc brake assemblies ●The electric brakes are NOT self adjusting, unlike most drum brakes on cars and trucks,need to be done when installed and periodically thereafter.If you cannot adjust yourself, please find a professional adjustment ●JADODE electric and hydraulic trailer brake parts offers 3 years warranty.Note make sure it matches you size,hub has to fit over