This is a 5x5x5 Hybrid Cube Mold, double-ended (Gen3).   Its overall OD is 7H x 7W x 6L, its ID is 5.25 x 5 x 5
This mold features a .25 inch headspace to make moving the mold easier when full.  
 
All Hybrid Sphere molds cast a Cube Shaped Blank that can be turned on a Lathe into a Sphere.  It does not produce a Round or Sphere shaped object.