Module with 4x 21700 3.6v 4900mah Cells

This is the best way to get one of the best cells on the market. These modules are overstock from modems. Each module has 4x 5000mah cells inside. They are one of the best 2170 cells on the market.

With the 4 cells each module comes out to 70.56wh (3.6v x 4.9ah x 4 cells)

You can pry these open at the seam to remove the cover. A good pair of cutters will help and just start at the corners and keep prying up. Took about 1 minute to get the one off for the photo.