K+E Magnet Back Mirror, # 71-6204; Keuffel & Esser

Description

K+E Magnet Back Mirror, # 71-6204; by Keuffel & Esser Co.
This is the larger, 4-inch diameter model, with a circular front-surface mirror that is reportedly flat to 1/4-wave over any 2-inch aperture.  The backplate has 3 magnetic feet with keepers; the contact feet are ground parallel to the mirror surface within 3 arc-seconds, according to the K&E Catalog #9 (1979 edition).  Comes with a snug-fitting red plastic cover, as shown in the pictures.
This item is in good condition; minor sleeks on the mirror face, but no damage (chips or cracks).  Some engravings on the metal skirt:  "Optical inspection", and inventory number(?) "8-1123 #2"  and some minor paint loss ...none of which affects function or performance.
The magnets are plenty strong to hold this 18-ounce item firmly on steel surfaces.
Typically shipped same day or next business day via USPS Priority Mail.