€¢ Ben-mor Strata Multi-Purpose 3in clothesline tightener €¢Quick releasing €¢For rope or cable of maximum 1/4'' diameter. €¢Ball bearing mechanism." €¢Not recommended for vinyl covered cable >>The economical all-purpose tightener is made of heavy-duty metal with a ball bearing mechanism. It is designed for ropes or cables up to 1/4 inch in diameter. Twist operated tightener adjusts for taughtness of the line.