What is this

Irv Kantrowitz

Michael Generali

It's from Latvia, and probably a revenue stamp.

Clifford Blazer, Jr.

Googled it. Says Latvian Railway stamp.

Jerold Backstrom

For bulk shipments of newspapers by rail. Issued 1926 with wavy line watermark and in 1928 with swastikas watermark.
Have several perforation varieties.
The wavy line watermark also has letters "Pactien Ligat Mills" and date "1858" once in the sheet, which increases value if part shows on the stamp.
1926 set has 10,15,20,50 & 1 Lats, 1928 issue is 5,10,15,50 & 1 Lats

Irv Kantrowitz

I want to thank everyone for their help.
Irv

David Hicks

If you want to throw it away ……….my waste bin is empty