Two Porsche TPMS sensors
 

For sale: two genuine Porsche TPMS sensors, fits 2010-2012 997s and 987s. Might fit other Porsche models in that year range, but not sure. I don't know if they will work for later Porsches, but they will not work with earlier ones (they changed the frequencies). I bought these sensors about a year-and-a-half ago, so they have plenty of life left.

New, they cost about $100 each. Asking $75 for the pair.