4 inch Square Clear Pot
The plastic pot is 4 inch (10.1cm) wide (diagonally) at the top, 3.75 inches (9.5 cm) tall. The base tapers to 2.5 inches (6.4 cm) wide. The advantage of a square pot is that you can pack more together than round ones.
It is made of sturdy, translucent plastic that allows light to get to your orchid's roots. This is very helpful for most epiphytic orchids that are used to having their roots exposed in their native habitat (in trees). This would include Phalaenopsis, Cattleya, Dendrobium and many other. Phragmepedium, Paphiopedilums, being ground dwelling terrestrial orchids, should have opaque pots.