2  format letters sent by Polish prisoner from KL Sachsenhausen and KL Gross-Rosen to his wife. Letter from KL Sachsenhausen is foldable letter/envelope model and it's complete with some stains. It was sent in 1940. The other one is very rare because is sent from Groß-Rosen concentration camp, and these are scarce. Very low number prisoner and also foldable type letter sent in 1941.

Both of them come with post-stamp.
Valentin Pieluzek was given number 28115 and block 66 in KL Sachsenhausen, and number 279 and block 6 in KL Groß-Rosen.

Very interesting set indeed.