4×6

Physical construction and design The unit that I was provided with is Hitech’s newer modular system, not to be confused with their previous offerings which featured a set number of filter stages in 2-stage and 3-stage offerings, and not to be confused with previous plastic holders.  The main plate of this holder is very nicely machined aluminum with thoughtfully recessed holes for the mounting screws.  The kit that I’m reviewing came with options for up to three drop in filters and a separate 105mm adapter.  It also came with some spare crews of varying size and nuts to put it