4mm to 6mm Shower Sliding Glass Door Hardware Rollers Kit

First of all I found it difficult to place an order. The purchasing program is not smooth. I also received the wrong product twice. The photo of the product clearly showed the item I wanted. Twice I was sent the wrong item. When I called back the phone sales person said she would call me back if when the warehouse checked on availability of my request. I never received a return call. I've spent over $30.00 on shipping charges and still don't have what I ordered.