1. Oil brake system makes the roller blind work smoothly and quietly 2. Limit switch system, allow adjusting the upper limit of the blind 3. Clutches on both sides of the blind, the operating chain can be fixed on either side according to your choice 4. Setting limit switch and changing position of operating chain without breaking down the blind 5. 38mm spring and chain operating roller blind system can be controlled by one operating chain only, thus, it solves the problem of leaving a long rope in the middle of the widow or on the floor when the plain spring roller blind was rolled up or rolled down 6. Adjusting the direction of the cover for the clutch to wall mounting or ceiling mounting without removing the fabric Maximum size: W2200mm*H2800mm List of attachments: 1) (left and right)bracket:1 pair 2) Up pipe envelop:1 each 3) D1.3mm*500mm spring:1 each 4) 1800mm beads chain(POM):1 each 5) control head:1 each 6) bottom lath end cap:2 each