From the boys at Thrillist:
This reusable, washable charcoal pad was invented by former National Guardsman Brian Conant. During a drill, BriCo passed gas while wearing his chemical attack suit and was amazed at how the charcoal lining snuffed the smell. Soon after, he developed a line of stink-fighting products for his company Flat-D, providing military-level protection for your civilian gas.
Conant's worker-friendly Chair Pad is thin and discreet: measuring 16 inches square, it lays inconspicuously across your seat like a welcome mat for your roaring sphincter. It can also be easily folded into your pocket and deployed anywhere, so you can fall asleep on planes or buses without fear of waking up to learn your row-mates have nicknamed you "Captain Beefski". [Link]