Factory built 20' insulated standard
20' & 40' insulated

These can be either ex-reefer containers, porthole insulated or standard containers that have been insulated.

As almost all shipping lines have phased out porthole insulated containers over the past 10 years or so the use of new "factory built" insulated standard containers has increased and will come to be the major supply in the future.

These are often used for conversions & modifications where insulated containers are required.
20' porthole insulated