The Model 687 Mouse Ventilator has a single piston and cylinder assembly. The tidal volume range is 0.1 to 1 cc in 0.1 cc increments. Setting the cylinder stroke between gradations it is possible to achieve finer resolution in tidal volume settings.

The piston travels to the end of the cylinder completely emptying the cylinder and minimizing the dead space of the breathing circuit.
Both models feature a numerical LED to display the respiratory rate which can be set from 18 to 150 strokes/minute. Volume and rate settings can be adjusted while the ventilator is running.

The 687 ventilator have four gas inlet and outlet ports: supply gas in, gas out (to animal), gas return (from animal) and ventilator exhaust. The ventilator exhaust can be attached to a column of water to achieve PEEP (positive end expiratory pressure) when long term animal ventilation is necessary.

Overhaul kits are available for the 687 and 683 ventilator models and are specific for the type of cylinder used. Overhaul kits include complete instructions and replacement parts.