Show sample as: 72-frame QuickTime VR or 360-frame QuickTime movie loop.    My periodic table poster is now available! Low-pressure sodium lamp. This is a low-pressure sodium vapor lamp (the most efficient type, but gives off an unpleasant yellow light). Source: eBay seller emmjane-ejc Contributor: Theodore Gray Acquired: 21 April, 2009 Text Updated: 21 April, 2009 Price: $35 Size: 12" Purity: <1%