This blank has a series of hearts on each side of the blank. The hearts are constructed in a manner that they remain in the same shape even when the blank is turned round. They will remain in the same proportions as you turn the blank down. I.E., they will get smaller as the diameter is reduced. The symbols on both ends allow you to construct two single tube kits from one blank.
These blanks require 2 or more pours of resin and we have noticed there are some small voids between the layers. This can often be cleaned up with some CA glue to fill in those voids, but the voids should be expected and this is why the blanks are being sold at a discount as seconds.