Sold in packs of 10.
Tests include:
Elementary 40 (2010) Long arena
Elementary 42 (2008) Short arena
Elementary 43 (2006) Long arena
Elementary 44 (2002) Short arena
Elementary 45 (2010) Long arena
Elementary 49 (2009) Short arena
Elementary 50 (2007) Short arena
Elementary 53 (2007) Long arena
Elementary 55 (2019) Long arena
Elementary 57 (2007) Long arena
Elementary 59 (2010) Long arena