These are the authentic Russian military undershirts, modeled after shirts actually worn by the Russian Navy, the Russian Airborne Forces (VDV), and the Russian Naval Infantry (Marines) under their uniform. This specific version has black stripes, long sleeves, and is made of ultra comfortable and stretchy fabric. These sailor shirts were manufactured using methods from the 1970s, making these "vintage" long sleeved telnyashkas have a more lightweight weave than the current issue ones. They are called "Telnyashka - Тельняшка" derived from the Russian word "Telo", which means "Body".
Please see approximate measurements below.