The insemination dose is wrapped with warmed ballast bags (note they have black liquid inside - do not inseminate!) so that the final volume of liquid, extended semen and ballast bag is between 120-180 ml. (cooling rate is determined in part by the volume to be cooled) Each ballast bag contains 60 ml. In this example, 2 ballast bags will be wrapped around the semen. Everything is then placed in the foam cup that is called an isothermolizer. The cover is then put on the isothermolizer cup.

The isothermolizer with the insemination dose and ballast bags is placed on top of both coolant cans. This is how the Equitainer was designed to be loaded and insures the correct cooling rate for the semen.