Very rare letter from sub camp of KL Auschwitz - KL Buna

Very difficult find any letter from this sub camp. Perfect condition !

Perfect condition

Kuś, Andrzej
(Prisoner number: 114708)
Born: 1902-11-14, Place of birth: Branow

The fate:
1. 1943-02-12, Auschwitz, coming to the camp
2. 12.2.1943, imprisoned in Block 2a as a police prisoner, 12.4.1943 registered as a prisoner of KL Auschwitz,

More info about KL Buna - Monowitz

https://en.wikipedia.org/wiki/Monowitz_concentration_camp