Blackview R30 Smart Watch for Men 1.83 inches colorful large screen and 3D curved glass that is carefully crafted under the borderless design concept are connected by nature, like a handicraft. The high-definition colorful large screen with 3D curved glass has higher resolution, better display effect and clearer. With 2Pcs straps of different materials, one is a silicone strap and the other is a woven strap. The size can be freely adjusted according to the wrist. The longest arc is 220mm and the shortest is 160mm. Comfortable to wear, suitable for the style needs of different occasions such as sports and work. Blackview R30 Smartwatch Takes Care of Your Health in All Aspects Heart Rate Monitor: - Adopted BIO1.0 pro chip and advanced heart rate sensor, monitor heart rate automatically every 5 minutes all day.