40 ft featherlite trailer has new spring assembly from featherlite is also the upgraded one. nice trailer tires are decent hate to sell but I never use it .I have not installed this spring unit yet still in box from featherlite so who everbuys this trailer you will have to put it on I don't have time right now trailer is being sold local so I reserve the right to end auction at anytime that means if you buy it and someone local has already bought it, it will go to the first person who has the money just to let you know sometimes I cant get the add off fast enough thanks.