Plastic T piece without valve for the windscreen washer jets fitted from 1980 onwards.
Takes 3/16" (4.8mm) hose GWW202M on all 3 outlets.
If you have 2 small outlets for 1/8" hose, see GWW404. This was known as 1/4" hose before decimalisation or 5mm but it is the larger bore size 3/16" 5mm.