About this item Trailer Brake Assembly Replacement For Most 5200-7000 Lbs Trailer Axles Replacement For Dexter Brake: 023-180-00, 023-181-00, K23-180-00, K23-181-00; Fits the wheel bolt pattern 6 lug or 8 lug, fits spline size #42 steel drum 5 Holes Mounting, Center Hole Diameter: 3-1/4″, Bolt Hole Spacing: 2.0″ O.C. Around the Top, Bolt Hole Spacing: 3.0″ O.C. Across the Bottom, Center Hole Diameter: 3.25″ Inches Package Include: 2 Pairs 12″x 2″ Trailer Electric Brake Assembly (Left and Right) These are fully assembled backing plates with shoes, springs, and magnets attached and ready to be mounted