Product details:

Works for patio doors with shades and smooth operating 8 foot patio doors (4 foot panel) Easy to install - just a few simple steps. Keeps children and pets safe from wandering out and gives you peace of mind especially if you have a pool. Energy Saver- Reduces cooling and heating by keeping the patio door closed. Speed adjustable to slow the door down as a child safety feature to prevent injury. For best results make sure to lubricate the tracks and any point the door touches the frame with silicone lubricant to minimize friction.