eSIMPhoney does not offer an unlimited data eSIM for Sri Lanka. All of the current plans for the country have a fixed data cap, with the largest available plan providing 50GB of data that is usable for 180 days.
If you need a large amount of data, you can choose from fixed‑data plans such as the Asia - 50GB plan, which costs $103.50 USD and is valid for 180 days, or the Asia Plus - 50GB plan at $119.65 USD with the same validity. These large‑data options may be more cost‑effective than buying a smaller plan and topping up repeatedly, but they are still bounded by the specified data allowance.