A ser is an obsolete unit of dry volume[1] in India. In 1871 it was defined as being exactly 1 litre (1.06 quarts). After metrication in the mid-20th century, the unit became obsolete.
"Ser". Sizes, grades, units, scales, calendars, chronologies. http://www.sizes.com/units/Ser.htm. Retrieved 2007-02-19.