Timing belt.   NOTE: If your unit has not been updated, you MUST order one each of the 3 parts listed here: 15006095 Timing Belt; 15006096 Upper Pulley; 15006097 Lower Pulley, so that the belt and pulleys match.   NOTE: This is a timing belt.  IF you DO NOT install the timing marks in the correct place you will tear this belt.  WE WILL NOT ACCEPT TORN BELTS FOR RETURN, because they were installed incorrectly --- they are not defective when installed incorrectly.