The ASAP Mustang "S Series" canopy is what we simply refer to as the standard square type canopy. 

The characteristics of the Mustang "S Series" canopy are very forgiving, with easy inflation, better handling and most importantly it is rock stable. 

The Mustang "S Series" is currently available in four sizes: the S380 for single seat applications, the S420 for single and two seat applications and the S500 and S550 which is pretty well the standard size in the two seat powered parachute applications.