The 18P4545 is a metal inner panel for 45 x 45 wallmount enclosures, part of Hammond's 18P Series of inner panels for 1418, 1447, PJW and PHW wallmount enclosures. It gives panel builders, electrical contractors and OEM engineers a flat, flanged back panel for mounting components.

According to the series specifications, steel panels are 12 gauge steel finished in white, and some larger panels in the series are 10 gauge. Larger panels in the series have two or four formed flanges; the drawing for this part shows a 0.75 in formed depth. Unlike most panels in the series, 18P4545 does not appear in the series ordering table, so the table gives no matching enclosure size. Hammond describes it as "METAL PANEL FOR WALLMT 45X45", and its drawing shows a 45.00 x 45.00 in panel.

The drawing dimensions the panel at 45.00 x 45.00 in with a 0.75 in formed depth and a 0.10 in material thickness, and shows eight 0.50 in diameter mounting holes on two 21.63 in pitches in each direction. Shipping weight is 60 lbs (27.22 kg).

Panel mounting hardware is not included; the series notes it is provided with the enclosure. The 18P4545 is RoHS and REACH compliant and ships in a box.