for aquariums describes the Economist. Nippura manufactures acrylic glass to use for huge aquariums. While Fresh Inc. is wondering, why they have chosen to stay small, there is probably an easy answer - the market may be small indeed.
This story very much sounds like the dozens of SMEs you come across cruising through the countryside of Baden-Wuerttemberg . Every village features a world market leader with products often totally unheard but used all over the world.