Exo-type enzyme that specifically cleaves the non-reducing terminal glycosidic bond of chitooligosaccharides (PubMed:16912928, PubMed:28130448). Catalyzes the hydrolysis of GlcN-GlcNAc to glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) (PubMed:28130448). Involved in chitin degradation (PubMed:16912928). Can also hydrolyze chitosan and chitooligosaccharides of various chain lengths (PubMed:16912928). beta-D-glucosaminyl-(1->4)-N-acetyl-D-glucosamine + H2O = D-glucosamine + N-acetyl-D-glucosamine Optimum pH is 6. Optimum temperature is 90 degrees Celsius. Glycan degradation; chitin degradation. Homodimer. Belongs to the glycosyl hydrolase 35 family.