Generally speaking, it is impossible to say whether the 335 model is subject to licence or not. We offered this product in two different versions, one version was purchase certificate free and the other version was due to a stronger spring subject to licence.
For this reason, we recommend that you visit gunsmith or a state firearms office, which can measure the speed of the diabolo and, based on this test, issue you with a confirmation as to whether or not it is an acquisition licence-free weapon.
We would also be happy to perform this service for you and prepare a corresponding letter of confirmation. The costs for this are EUR 75.00 incl. VAT, packaging and shipping.