Rollei 4x4 is called Baby Rollei, Launched in 1931. The lens is Tessar 60mm F3.5 or F2.8 and used 127 roll film. The shutter is B, T, 1 - 1/300 sec. It is not a automat for film winding.
The new version was launched in 1957, had gray body. The lens was Tessar 50mm f2.8 in early version and was changed to Schneider Xenar 60mm F2.8 in late model.
The shutter was Synchro-Compur, B, T, 1 - 1/500 sec and automat for film winding.