ISEO R11 8973 UK Oval Profile Cylinders with key outside and thumbturn inside. 11 Pin flat reversible keys. Available Keyed to Differ (with 3 keys per lock), Keyed Alike (2 keys) & Master Keyed (2 keys). Over 1 million key differs. Excellent and versatile Master Suiting possibilities with added security. One Master Key supplied Free of Charge per Master Suite order.