"Particulate Respirators"

This set is a simple and inexpensive tool that measures vital capacity.

The AquaClear Power Filters features a unique multi-stage filtration system that provides complete mechanical, chemical and biological filtration for superior water quality. The Power Filter has a filtration volume that is up to seven times larger than comparable filters. It also allows superior contact time with filter media. The filter preserves beneficial bacterial creating a stress-free environment for aquarium inhabitants and maintaining clear aquarium water.

This system shows interdependence of circulatory and respiratory systems.

Easy student modeling.