US$ 55.99
each lens stowing into the housing for pocket-portable classroom
dropping into the Worcester Circuit Board Kit for telegraph work
a step up from the 70mm model with extended pole separation that gives field-mapping experiments more room along the magnet axis
the elongated triangular geometry handling longer ray paths for total internal reflection and beam-redirection optics
Steel Folding Quadrat, 0.5m Square Length_75mm each lens stowing into theBolt together folding quadrat of white coated steel rods, forming a half meter square for ecological field sampling and population count fieldwork.