VEVOR Electric Trailer Brake Assembly, 10 x 2-1/4 Inch, 2 Pairs Self-Adjusting Electric Brakes Kit for 3500 lbs Trailer Axle, Backing Plates for Braking System Part Replacement, Fit for Trailers, RVsSelf-adjusting Electric Trailer Brake KitHigh CompatibilityHeavy-Duty Downhill StabilityLong Lifespan of ≥30,000 kmWide ApplicationProtective Dust ShieldElectromagnet Specifications: 10 in / 254 mm,Brake Pad Dimensions: 2.26 x 0.19 in / 57.3 x 4.8 mm,Product Dimensions (Outer diameter × Height):,Compatible Trailer Weight: 3500 lbs / 1587.6 kg,Brake Pad Friction Coefficient: 0.48,Brake Drum: Φ10.83 x 5.28 in / Φ275 x 134 mm,Brake Dimensions: 10 x 2-1/4 inch,Magnetic Force: ≥450N,Brake Drum Dimensions (inner diameter): Φ 10 in / Φ 254 mm,Flange Bolt Count: 4, PCD 4 in / 101.8 mm, 7/16-20UNF (Length: 0.8 in / 20 mm),Service Life: ≥30000 km,Package Contents: Set of 2 (4 brake shoes + 4 brake drums),Main Materials: Gray Cast Iron & SPHC & Q235,Brake Drum Bolt Count: 5, PCD=5.63 in / 143 mm, 1/2-20 UNF,Item Model Number: 3500-4-1,Product Weight: 124.6 lbs / 56.5 kg,Brake Shoe: Φ11.22 x 2.87 in / Φ285 x 73 mm,Voltage/Current: DC12V/2.5-3.6A