The 12.5oz lump weight machined from a solid bar of stainless steel, and threaded through its entire length, 5/16" UNF.
It is exactly the same shape and size as a stack of three of our Countersunk 4oz weights. Comes with a 5/16" Grubb Screw for attachment.
 
This weight offers great value, as it costs less than two 4oz weights. 
It also means that thouse stacking large quantities of weights together do not need very long 3 to 4 inch bolts OR threaded bar to hold everything together.
 
Because it is fully threaded it is also very useful for adding Flex Ball Style dampeners on to the end of the weight stack- with just a couple of weights hanging from the dampener.