*Why "D4"?  I normally get asked,  and will get jumbled with A5 (that is a climbing quality), and D5 (which stood for "Deuce5"), two models I are already associated with in the past.  My nickname in Yosemite was https://allenuedu109364.pointblog.net/how-d4-can-save-you-time-stress-and-money-70097218