This is a new silicone Castlemolds mold made by Hirstarts, Mold #204 Large Cracked Floor Tile Mold.

These 1 1/2" floor tiles have a smooth worn surface with random cracks.

Mold is approximately 5.5" x4.5", 14cm x 10.5cm.

Mold is designed to work with 25-30mm scaled figures. However, they can work for different scales depending on how you use them. 

You may notice a white residue on the mold, this is corn starch/baby powder. This is to stop the molds sticking to each other.