An exemplary pump-head includes a pump housing having first and second housing portions forming a pump-cavity and a magnet-cavity. The pump-cavity contains a movable pumping element, and the magnet-cavity contains a driven magnet coupled to the movable pumping element. The magnet is driven by a moving external magnetic field, which correspondingly moves the pumping element in the pump-cavity in a pumping manner. The second housing portion has inlet and outlet ports and defines at least respective portions of the magnet-cavity and pump-cavity. The first housing portion is detachable from the second housing portion to allow the pumping element to be accessed and carried away with the first housing portion, without disturbing the second housing portion.