13-blades KMZ Helios-44 M42 58mm f/2 M39 №0042456

This lens is suitable for SLR cameras and any mirrorless cameras.Sometimes it can be hard to screw into M42 bayonets of old cameras. This is because the thread is made to fit tightly in modern adapters. It screws into all factory adapters easily.The thread is installed using a glueless method, metal-on-metal tension. This is quite reliable. However, I recommend not to screw the lens into the camera with all your strength, so as not to tear off the thread.