It’s quick & easy to understand the sizes of tap aerator with this video. Pay attention to this video and get to know the size of aerator installed on tap.
Size M = Rs 1 (One) Coin (launched in 2014) = Outer Dia 22 mm
Size L =Rs 2 Big Coin = Outer dia 28 mm
Size S = Outer Dia 18 mm
Look for same size detail of Aerator while buying on Eco365 Fixtures online.