The rotisserie on sale is for the newer Genesis (26 1/2" from outside edge to outside edge) however I THINK the spit may have the rotator shaft ground down to fit the older one too. Measure you grill base from edge to edge and check that against the rotisserie on sale. If the rounded part of the spit will fit in the slots of your grill, you'll be good.
(I had to modify and older model rotisserie to fit in the newer Genesis by grinding a new "rotator slot" on the spit. Works fine.)
Rich