Endo-hyaluronidase that degrades hyaluronan to smaller oligosaccharide fragments. Has also chondroitin sulfate hydrolase activity, The best substrate being the galactosaminidic linkage in the sequence of a trisulfated tetrasaccharide. Random hydrolysis of (1->4)-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. Optimum pH is 4.5-5 (for chondroitin sulfate hydrolase activity). Optimum temperature is 37 degrees Celsius. Detected in placenta and skeletal muscle. Belongs to the glycosyl hydrolase 56 family.