These products are sold for example here:
http/www.ebay.com/itm/Asus-UX305FA-FB012H-Intel-Core-M-5Y10-0-80GHz-Win-8-1-SSD-90NB06X1-M01840-/271755482873
http/www.ebay.com/itm/Asus-UX305FA-FB003H-Intel-Core-M-5Y10-0-80GHz-Win-8-1-SSD-90NB06X1-M00070-/301506759437
They look like identical products to me. However, they have different model numbers, so there probably is a difference?
http/www.ebay.com/itm/Asus-UX305FA-FB012H-Intel-Core-M-5Y10-0-80GHz-Win-8-1-SSD-90NB06X1-M01840-/271755482873
http/www.ebay.com/itm/Asus-UX305FA-FB003H-Intel-Core-M-5Y10-0-80GHz-Win-8-1-SSD-90NB06X1-M00070-/301506759437
They look like identical products to me. However, they have different model numbers, so there probably is a difference?