Which global forex card is good ?

I am planning to get my first international travel card. Since i dont know much about forex trade, i dont know how the lock-in feature of other forex cards will be of use to me. The niyo global card doesnt have a lock-in feature.

On all other aspects, the Niyo global seems to beat all the other cards out there. Or do they offer very bad currency conversion rates?

Any advice is highly appreciated. Thanks in advance.