As noted previously, we use soft-sided, bubble-type Trexler isolators. We do not have experience with solid-sided isolators, and those are not addressed here. Trexler isolators can be made to order in many different sizes and shapes, but all contain the same basic components: plastic canopy, entry port, gloves, and inflow and outflow filtered air supply (Figure 6.1). The polyurethane canopy is inflated by a ventilation motor that passes air through a HEPA filter. The canopy inflates to a positive pressure, then exhausts through a second HEPA filter. The only access into the isolator is through the port. The port has a double air-lock system consisting of two barriers: the inside cap and the outside cap. When the isolator is in use, only one of these barriers is removed at a time.