A: Screw-barrel magnifier with removable objective lenses. The lenses shown fit into the base of section B.
B: Body tube of the simple loupe-type magnifier.
C: Flea Microscope with its specimen pin.
Screw-barrel magnifier with removable objective lenses. The brass mount holds the single biconvex lens. Free lens (*) is one of the two concave specimen glasses.
Screw-barrel magnifier, disassembled. A: Body tube (objective facing away), B: Specimen glass, C: Specimen assembly.