sundance filter  6540-501
sundance filter  6540-501 Micro-Clean Hot Tub Filter
The MicroClean system is used in the following Sundance Spa models:
  • All Current 780 Series hot tubs
  • 800 Series: (Altamar Cameo Capri Caprio Marin Maxxus Optima) from 2002-2005
  • Sweetwater Series: (Bahia Palmero Cayman Caprio) in 2006
  • Metro 2004+
  • Tango 2002-2003
The filter is made up of two parts sold separately- the 75 sq ft filter similar to a standard filter you might see on another brand's hot tub  and a disposable white micro-filter Part #SD116. Purchase the disposable micro-clean filter here.
If cared for properly the 75 sq. ft filter can last up to two years. 
Looking for the piece that holds both filters together? Find that adapter here SD118.