Kreutzer was a well known composer and conductor in his time (particularly for his operas) and he also wrote chamber music, including these duets for clarinets. They are also available in an edition by Peters (no 8329). This edition has some differences in articulation, which are based on performance experience, and the long repeats in the first and third movements have been omitted; the reality is that you are unlikely to perform such long movements with all the repeats. Any of the movements can be performed in isolation. They are very attractive (if not musically profound) pieces and make good concert and teaching material. The pages have been arranged so that you can print the whole thing double sided (on A4 or US letter) and end up with the page turns in convenient places.