VEVOR Electric Trailer Brake Assembly, 12" x 2", 2 Pairs Self-Adjusting Electric Brakes Kit for 7000 lbs Axle, 5-Hole Mounting, Backing Plates for Braking System Part Replacement (2 Right + 2 Left)

Yes, this fits dexter 284560 axle.

 We recommend using a 10-inch model with a load capacity of 3,500 pounds. If this answer does not resolve your issue, please contact us again for assistance.

No, this product does not include the bolts needed to bolt it back onto the trailer. It only includes bearings — no bolts or nuts are provided.

 It will also adjust automatically when reversing. If this answer does not resolve your issue, please contact us again for assistance.

No it doesn't. If this response does not resolve your current issue, please contact us again for assistance.