Pre WW II Czech VZ 23 / 24 Bayonet. This is either the VZ 23 or 24. It is marked CSZ over a D which means it was made for an artillery battalion. There is also an E##37 on the tang. On the crossguard or barrel lug its marked 423 and a symbol I don't recognize. The scabbard is not marked. Beautiful bluing on the blade with some slight nicks. Push button / press stud works well. I am not an expert on these and there are many variations out there. Please see the pics for details.