Yes.

It's like this. You can reload any amount you like into your card, any time.

Now if you want to use it as unlimited, you need to renew the subscription. Each subscription cost RM100 (deducted from your card) and good for 30 days. Next month renew the subscription again if you wanna use it as unlimited (make sure have enough balance). If you don't renew, it will become normal myrapid card i.e. pay per use.