Standard Twin Packaged Blowers are the most popular KOOLTRONIC Packaged Blower. These blowers achieve exceptional performance through use of the largest possible blower housings and wheels. Each contains a quadruplex centrifugal blower powered by a single precision ball‑bearing motor. These widely‑used Standard Twin Packaged Blowers deliver air from more than 50% of their 17'' [431.8mm] width, while conventional blowers deliver air from only about 30%. Internal neoprene isolation mounts reduce transmission of vibration and AC hum to the enclosure. Long service life and trouble‑free performance are assured through the use of precision ball‑bearing motors in all models and by the dual inlet quadruplex design, which uses intake air to cool the motor.