Product review (5 stars): No Sillyness
Fits perfectly with a well made precise housing that is nicely finished with no sharp edges or flash.  Good quality O rings. I am told by the seller that the carbon block is coconut which is probably the best type of block.  It is sans the frivolous hex bolt head that some filters have at the bottom end.  I would rather see resources applied to the structure of the filter than to a token hex.  It is analogous to those silly "spoilers" on cars that do nothing but obscure rear vision,  add leak points,  make the trunk lid heavier,  and waste resources.  If a person is too weak to turn these little filters by hand, they are probably too weak to hold a wrench to the hex.