For professional modification of the 8215 / 2813 / 8205 / ST16 movement. Diameter 40mm lug size: 20mm. Excluding the movement and strap. Please allow 0.1- 0.5 cm error due to manual measurement. The colors may have different as the difference display, please understand. Customers satisfaction is very important to us! Please give us the opportunity to resolve any problem. We understand the concernsand frustrations you might have, and will try our best to resolve the issues.