Built-in Bluetooth compatibility allows easy connection to the app for prayer time reminders. Integrated button for convenient daily count tracking at any time. Counter vibrates at counts of 33, 66, 99, or 100 for easy feedback. 0.49-inch OLED display shows time, number of chants, and prayer times. High-capacity battery lasts for 3 days and can be via USB. The counter has a counting range of 99999 and operates on an input signal voltage of 1.5V. It is available in sizes of 18mm, 20mm, and 22mm. Color: Black Material: ABS Package Contents: 1*Counter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.