This is the original Pipet Aid which probably set the standard for most automated pipetting. It is powered by a small 110 VAC 4 watt compressor. It appears to work as it should despite its 30 years of service.
According to the manufacturer:
Electric pipet controllers never needs recharging. This design prevent cross-contamination with optional tissue culture nosepiece, or use optional air filtration unit for vacuum and pressure lines in biohazardous environments.
If you find the item is not as described in the ad it may be returned for a purchase price refund. Generally, all of our items have an inspection warranty which kicks in upon delivery for a period of 7 to 14 days. It is not an operational warranty as most items sold on DOTmed require biomedical certification before use. If you require additional coverage please contact us prior to purchase.