ART SpiderJack 2.1 Basic for 11mm-13mm Lines

Although similar in concept to the Sport, the SpiderJack is a more sensitive performer, rewarding skilled climbers with an amazing sense of line control. Operating on a wider range of rope diameters than the Twin or Sport, the Spider requires threading rope into position for use, a non issue if you use only one end of line. You will instantly recognize smoother rope action while ascending and descending. Merely pulling on line above causes the Spider to gobble rope with a voracious appetite. This same frictionless hunger for loose rope makes branch walking and canopy exploration a gratifying reward for getting out of bed. And when it comes to descending-look out, here comes the Spider...man! For 11mm through 13mm lines.
 
Resides close to the harness similar to an eye to eye split tail. Device only.
(Cannot be attached midline.)

SpiderJack 2.1 Basic by A.R.T. instructions (PDF)