5-inch "Vest Pocket" Slide Rule
Frederick Post model 1444K [1937-41 and 1949-1971].  (some [1971] marked 1444)
Teledyne-Post model 44DA-440 [1972+]
Hughes-Owens model 341 3425
Hemmi model 34RK

One of Post's most enduring models.

For a short time about 1971 some Frederick Post boxes marked "1444K" contained rules marked just "1444" (no "K").  It appears that Post decided to drop the "K" from 1444K  (and the "W" from 1452W) but changed their mind after the newly marked rules arrived from Japan but before the boxes and catalogs were printed.  (Or maybe it was just lack of communication between two departments.)
1949 Frederick Post General Catalog,  Pages 70-71

Note the unusual S scale on this specimen.  On most Post slide rules with [S, L, T] on the back of the slide the S scale was keyed to the B scale   (i.e., angles on the S scale ranged from 34' to 90o).  But from WWII to c1955 the S scale was keyed to the C scale (i.e., angles ranged from 5o 44' to 90o)   This specimen, which dates from 1952, has this unusual S scale.  Click here for a discussion of S scale arrangements.