From the Tri-State FPD Facebook page: 

Our “new to us” fire apparatus. Engine 120 is a 2009 Pierce Impel pumper that formerly served as Lisle-Woodridge FPD Engine 56/54. Engine 120 will serve as a reserve engine.
#chicagoareafire.com; Firetruck; #Pierce; #Impel; #Tri-StateFPD;
 
#chicagoareafire.com; Firetruck; #Pierce; #Impel; #Lisle-WoodridgeFPD;
thanks Martin