Item #70812 -HTS.    The HTS Suspension Systems Options.  HTS 21K . 23K, HTS - 26K , HTS - 31K and HFS Four Spring. These suspension systems come in two options (1 Pair) or (2 Pair). Available in 1/25 - 1/24 or 1/16.
 
Because of the limited space availabel in the drop down menu  when you see the word SPLIT this refers to the multi part version or multi piece version.