Used Kalyn Siebert Tri Axle Low Bed Trailer for sale. Features: Hydraulic Detachable Neck, Predator Gas Pony Motor, Mounts for 4th Axle, Swinging Outriggers, Flat Deck, Open Bolsters on Rear, and more. Hundreds of new and used trucks, trailers, and parts for sale at Coopersburg & Liberty Kenworth. Three convenient locations: Coopersburg, PA (near Allentown), Swedesboro, NJ (near Philadelphia), and TRP Parts (Pottstown, PA).