This bolster allows the purchaser to install Protocraft couplers on a Lionel PS5 Gondola. It is designed to be used with my 100ton Roller bearing trucks, but there is also a realistic looking conversion bolster that will allow you to mount the newer Atlas O 100t roller bearing trucks to this as well. This comes with brake pipe detail and is designed so that you can drill and tap the two mounting screws from the Protocraft couler assembly to mount this securely to the car, However, this is designed to slip over the hole left by removal of the Lionel truck. This can only be printed in frosted detail plastics and thus is fairly brittle. Make sure you drill the mounting screws for the coupler pocket and truck carefully to avoid splitting.