Donegan Optical Company Inc
Classic Series Magnifiers w/Acrylic Lens & ABS handle

2 x 4" 5 x 10cm Rectangular w/Bifocal
Walthers Part # 240-625, p. 856 Walthers 2012 HO Scale Reference
A scale, $12.69, currently in stock at Walthers

 
These lightweight, handheld magnifiers feature ABS plastic handles and acrylic lenses that are produced to high opthalmic standards.