The 046MCG Expan Drive Set with Gray Metal Chain from Manfrotto enables you to easily and conveniently raise or lower the rolls of background paper without having to lower the support stands. Using two expandable technopolymer inserts, the system supports one roll of seamless paper. When you tighten each side, the drive inserts expand from 1.8 inches to 3 inches for gripping the roll of paper tightly from the inside. One side of the system consists of a big gear with several teeth. A metal chain attaches to these teeth. This metal chain enables you to raise and lower the background paper conveniently. The other side of the system features an adjustable tension drag.