This is the identification number for a Quadrant shower door single sliding, model 1691. The '16' indicates the year of manufacture, 2009; the '09' indicates the month of manufacture, September; the '11' indicates the size of the door; the '96' refers to the finish of the door, brushed nickel; the 'B' indicates the type of door, bypass; the '06' indicates the type of handle, round; the '00' indicates the type of glass, clear; the '61' indicates the type of hardware, bright brass; the '10' indicates the type of strike, snap.