All time Polka containers are completed with fine quality materials. All these containers are very handy and convenient to store your food items. These containers has ranges starts from 125 ml to 5 litre. The lids for this range are of different sizes but same to the range (501, 502, 503 respectively). So, there's no confusion for the lids to close the containers. Although, after putting the lids, the containers can stack one over the other. There's a reason why the containers are said to be Polka Container because of the lids, it has a unique texture of small circles, known as Polka.