Aspirin, Xerox, Jello, etc. Same deal with Telesteps. Originally designed and exclusively manufactured by a Swedish company.

Patent ran out and others rushed in. But before the patent expired I was hired by a New Yorker named Len ...... to evaluate the units he was licensed to make in USA.

I discovered what the problem was. Len had to give up after 6 months as the American machinists that he hired could t duplicate the precise standards that the Swedes are capable of. (Home Depot had to stop selling the American defects---Interestingly they used Swedish made units as floor demos)

I own one of the last units made by the Swedes before the patent expired.
It is a unit that no longer has the defect that caused collapses and lock-ups.

There are many people making these now. In USA some ex Russians, elseware Chinese, and Japanese. I would trust the Japanese versions.

I guard my steps with the ferocity of a Nile Crocodile. I am very picky who I let climb my genuine telesteps.