The law in germany is quite vague. some points are clear. Fixed blades are legal up to 12 cm, one hand opening knifes are illegal, regardless of blade length, assisted opening blades are illegal (except if teh width is more than 1/3 of teh length and blade length below 8 cm afaik). Double edged and butterfly opening knifes are illegal to carry. I´m not sure about the locking thing, but i believe one hand opening alone is enough to make a knife illegal to carry. Owning such knifes is allowed.You can carry a OHO when you have a "fair reason" as hiking outdoors, fishing, working etc.Multitools are mostly exempt, but not by the law (a one hand opening blade is a one hand opening blade after all) but by common sense from the police.I am not sure why you would ban one hand opening knifes, regardless of the length, but allow carrying 12 cm long fixed blades, but i guess knife laws don´t always make sense...