PreSonus Pull-Back Sling for CDL Series Loudspeaker ArraysPreSonus Pull Back Sling for CDL Series Loudspeaker Arrays The CDL Rigging Sling is required on all installations that include 4 or more CDL series loudspeakers in a vertical array. Additionally, in installations using the CDL Rigging Extension Bar deployed with an upward or downward tilt of 12 or greater, the CDL Rigging Sling must be utilized. Key Features Pull Back Sling for CDL Series Loudspeaker Arrays Technical Specifications Size (H x W x D) 9.