8" cooling fan 10" cooling fan 12" cooling fan 15" cooling fan Thin Fan, various sizes, lower CFM (quieter), only 30mm thick, light weight material. longer pull solenoid (door opening systems) Standard solenoid Gas Charged spring (40 or 60#) (door opening systems) Control Unit (all systems include a control unit except the K9 Release) Pager System, complete with glass mount antenna High gain pager antenna (5' long!) K9 Breeze temperature readout with sensor