I had traveled to few Africa nations and European nations and was earlier using Matrix. I was very disappointed with matrix as they charge high rates and are only in 30 nations.
But this Reliance World SIM is there in 160 countries and great voice quality and even works in cruise which Matrix doesn’t.
No Rental , No Deposit and you can buy it from any Reliance Websworld.
http://www.reliancepassport.com
https://reliancepassport.com/globalsimcard.html.
They have this Feature of Call forwarding..that means if I reach India , I can call forwards all my calls to the International SIM(+44 number) to my Indian number i.e. Airtel Post Paid SIM for just 1 Rupee