It is, what the website says. I've compared that rate to XXSIM, their 2GB package is only available in the EU countries (Zone 1). If you head over to travelsim, they also state "Zone 1" for the 2GB data package at the price ov EUR 36.
See the countries included here
Travelsim:
https://travelsim.com/data-roaming-packages/
XXSim:
https://xxsim.com/en/dictionary/firs...ml?menu_id=136 (scroll down to data packages
air baltic card:
http://airbalticcard.com/information/mobile-web/ (see package 11, only 1GB)
This seems all to be Zone 1 of the Estonian providers.
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Mobiles: iPhone 7+, iPhone 7, iPhone SE, Blackberry Priv, Honor 8, Lumia 950
Prepaid-SIM: 3 UK, Save Money Sim, Toggle Mobile UK, XX-Sim, Koko Mobile