From the Andersen website:
Do I need safety chains with my Ultimate 5th Wheel hitch?
If you plan on traveling cross country and you want to make sure you are in compliance with state laws that vary from one to the other then you should install safety chains.
We know that California, Indiana and Texas have safety chain requirements. Indiana safety chain laws are usually only enforced for commercial applications, but they informed us that if the hitch was a ball type, chains were required. Many states do not require the safety chains, which is why they are not included in the initial package (cutting out extra cost for the majority of customers).
We do sell a Safety Chain kit –
part # 3230 $59.99– that includes the chains and bracket hardware necessary for installation.
Attaching safety chains: Each vehicle is different but all gooseneck hitches when installed will also have a spring loaded bracket or 'ears' by the gooseneck ball that the safety chains can attach to.
Attaching the breakaway cable: On the pyramid shaped base of our hitch there is 1/8" bars welded in between each leg and the breakaway should be clipped to it.