It seems that a Indian gentlemen from Lanasia flooded the market with thousands of earth leakage and CB's units, which he sold to the local suppliers.
He appeared in court and was sentenced to time and heavy fines, so, if you are in the gauteng area it would be worth checking your purchase before paying.
I am waiting for document proof from CBI manufacturing with regards to there Isolators being fed in the bottom or top, they say top or bottom makes no difference. I have never been sure on this.