Larry, the salesman came to my house and gave me an estimate for 8 windows. this is what it reads: window with outside wrap with low-e, no grids. $339.($2712) qualifies for $84. tax credit, haul off for house $75. I agreed, contract drawn up. series 4000 DH All-welded white_ $205 $1640. So, not know 'their' terminology, i thought that he was writing this up as he said and wrote on the estimate. (i also pd for 3 windows for my in-laws). on the contract, it states that series 4000 & 6000 qualifies for federal tax credit. Also, 9 custom... read full review »