From Frazer, Ltd. on Facebook:

Check out the new Air Supply Truck for Milwaukee! The purpose of this vehicle is to be a logistical apparatus to help move bottles from either station to station or they’ll show up on multi alarm fire scenes.
#chicagoareafire.com; #MilwaukeeFD; #FrazerBilt; #FireTruck;

Frazer Lt photo

#chicagoareafire.com; #MilwaukeeFD; #FrazerBilt; #FireTruck;

Frazer Lt photo

#chicagoareafire.com; #MilwaukeeFD; #FrazerBilt; #FireTruck;

Frazer Lt photo

#chicagoareafire.com; #MilwaukeeFD; #FrazerBilt; #FireTruck;

Frazer Lt photo

thanks Martin