They are the new design ( 2 years ago now), single rollers. The double rollers are overkill for the street IMO. I put a set on the Mule and could hardly tell the difference. Mark put a set on the PT-chaser and said he could feel a change on the track. The drag racers get the most benefit from the feedback we've got.
They turned out pretty nice for 40+ year old perches.
I got a special set sitting here for you Jake. :lol