This article presents a new type of 4K pulse tube cooler that we refer to as the VM type pulse tube cooler. What is different from the GM and Stirling type pulse tube coolers is that a thermal compressor is used instead of a mechanical compressor to provide the pressure wave for obtaining temperatures below 4K. Our research focus is on developing more efficient 4K coolers and coolers that can provide temperatures below 2K with ³He. The whole system can be divided into two independent subsystems: the VM side, and the GM side. On the VM side, the thermal compressor has no moving components at cryogenic temperatures and is made up of a room temperature displacer, work transfer tube, and one regenerator. This compressor utilizes the temperature difference between liquid nitrogen and room temperature to generate the pressure wave for the 4K pulse tube cooler. The GM side is only used to provide some precooling power at about 20K for gas entering the Er₃Ni regenerator in the VM side. Using ⁴He₂ a temperature below 4K has been obtained with a pressure ratio near 1.3, working frequency of 1 Hz, and charge pressure of 2.1 MPa. The cooling power at 5K is about 12 mW.