4 1/2 inch plastic pot. No side slits
The four and a half inch round pot is 4.5 inches wide at the top, 4.5 inches tall and 3.25 at the base. It is similar to the 4 inch pot, but flares out at the top.
It is made of light weight, 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.