A biosensor has a hydrogel in a rigid and preferably biocompatible enclosure. The substrate web is printed with an ink composition to form an ink film on the substrate web. The turning member may be turned for a selected displacement in the housing member to change the angle of a hanging parasol relative to the supporting bracket to block sunshine, and a displacement element of the anchor means may be moved to constrict the adjusting element at a selected position to keep the hanging parasol stationary at the selected angle. A function mandrel separate from the tubing hanger is engaged with the production tubing and positionable inside the function spool bore.