From their website:
The main part of this release is a line of round miniature bases. Available sizes in the first release are 25mm, 40mm, 60mm round and 25mm x 50mm bases with rounded corners.
All sizes are available in both normal resin to represent rock or a clear resin ice.
We will be releasing the popular sizes of rectangular fantasy bases in our next release sometime in March. If demand is high enough we will do some of the less common base sizes later on.