HR513
ø5 hole @13.5mm pitch. 
11% open area.

HI513
ø5 hole @13.5mm pitch staggered. 10.8% open area.

HR713
ø7 hole @13.5mm pitch.
21.1% open area

HI713
ø7 hole @13.5mm pitch staggered. 21.1% open area

HR727
ø7 hole @27mm
pitch. 
5% open area.

HI727
ø7 hole @27mm
pitch staggered. 
5% open area.

HR827
ø8 hole @27mm
pitch. 
7% open area.

HI827
ø8 hole @27mm
pitch staggered.
7% open area.

HR927
ø9 hole @ 27mm
pitch. 
9% open area.

HI927
ø9 hole @ 27mm
pitch staggered.
9% open area..

HR2540
ø25 hole @ 40mm pitch.
31% open area