You are admiring an amazing specimen, an Terebra knudseni (Bratcher, 1983) measuring 51.2mm and graded Gem...classic "Auger" form with an amazing color pattern & ribbings are displayed...a very attractive specimen.  This beauty was collected at lowtide off Balabac, Palawan, Philippines.  A member of the very popular Terebridae family & a wonderful addition for your collection.  Thank you for visiting our store this afternoon...& an excellent choice, too.