The A21 ia a ready-to-use GPS watch / tracker, with many useful additional welfare functions.
It has the capability to:
1) announce the time (double press button),
2) send SOS app alerts & calls to up to 2 numbers (long >3sec button press),
3) send geofence / safety zone app alerts,
4) allow historical look-back - over last 3 months,
5) voice monitoring / silent call* to listen in,
6) Locator - tracker makes a noise - to you help find it. 
* With the default SIM, voice and phone functions are disabled. Details on voice/phone option SIM functions available on enquiry.

When purchasing an A21 pendant tracker, it is also necessary to add an annual subscription GPS Watch subscription to your basket. Follow link:  Watch Subscription

Phone App:   The A21 tracker doesn't use the TrackServer phone app, but rather the Aibeile phone app, for which QR codes appear below. Aibeile -  downloadable from the Apple or Play stores
To change tracker settings, use the commands options in Aibeile, rather than by sending it SMS messages, which may not have the desired effect. Contact us if you need help.

Web App (for larger screen devices):   The A21 tracker does not use the TrackServer user interfaces, but rather the GPS Tracking Station at: https://www.aibeile26.com - click link:>  aibeile26.com.
When using it, select the English language / Union flag, then click on either the Account tab (for multiple devices) or the ID No. tab for a single device.
Enter your Account name, or the ID number from the label on its Watch box, then the Password as provided on your GPS2Find invoice. These can be subsequently changed.
Select the "Monitor" tab.

Below are links to Training / User PDF documents to download. These explain the operation, the use of the Aibeile phone app and the GPS Tracking Station web app.

Aibeile phone app Guide - DOWNLOAD LINK

GPS Tracking Station Web App Guide: DOWNLOAD LINK

The A21 comes with a magnetic coupling charging cable and a SIM (nano - 4FF) already installed. Any voice charges incurred will be billed back to the associated customer.

Physical dimensions: 5.0cm x 2.7cm x 1.7cm.  Weight: 38gm
Characteristics:
► GPS chip: MTK2503, built-in high sensitivity ceramic antenna
► GPS,WIFI and LBS three positioning modes
► Built-in quad frequency PIFA antenna
► GPRS: Class12
► 3 Location reporting time intervals: 1 min, 10mins, 60mins.
► GPS Positioning accuracy  5～15m, dependent on satellite reception.
► Build-in MIC and speaker
► Button (power/ SOS button)
► Battery: 1000mAh
► Standby time: 10-15 days. Utility time: 6-10days (hourly reporting)
Features: : ► Compatibles with Android and IOS phone
                   ► GPS+LBS+WIFI three mode positioning
                   ► Real-time tracking on Google map
                   ► Automatic alarm when out of  range
                   ► Historical data retained for 3 months
                   ► SOS emergency button to send alert to app, not SMS/email.
To turn On: single long (ca. 3sec) press of On/Off button..
To turn Off: Ten short presses of On/Off button.