Based on the picture they definitely look like unprotected cells to me. In a protected cell you will see a layer of shrinkwrap over that factory wrapped cell. You’ll also find that there are several varying features in 18650 batteries (Because they’re the most common there are many options).
The varying features of NCR18650B 3400mAh cells are: Flat top vs Button top. Protected vs Unprotected. You can have flat top unprotected, flat top protected, button top unprotected, button top protected.
The cells in the ebay auction are flat top unprotected based on the picture.