Please help me identify this cassette I recently found this cassette that appears to have only 5 speeds. No locking or anything. Is it incomplete? Can it still be used with a normal freehub (with spacers of course)? 

Thank you!
It's an incomplete 7-speed 11-34 Shimano CS-HG50, the model name is written on lockring. I think you can use it with spacers/lockring or source missing parts from another 7 speed cassette.