These clip-on chain stops will stop your blind over-rolling. Stops blind going up or down too far.
This can be a problem where you have a long or continuous loop chain. These stops should fit most white cord chains including number 6, 8 and 10 chains in plastic.
Also, ideal if you have several blinds in a bay or room and put them all on the chains in the same place so all the blinds pull up to the same level easily.