Here is the reply I got from the E Bay seller of new Shuguang tubes in the UK. Seems quite laughable and will be avoided. The Trade standard seems to be 90 days.
"Since we don’t have a manufacturer guarantee due to the time getting them from the manufacturer to the time they get sold, any guarantee given by the manufacturer expires.
The only guarantee we give is as per eBays rules. If you receive an item not as per description or faulty item, in our case, you have 14 days from the date of the item received to report or return the item for refund."