Tensioner Slat Kits from Furnacc. Easily strengthen the existing flexible slats on your slat bed. Each kit consists of 5 thin 6mm flexible slats and 10 plastic tension adjusters. This is sufficient to fit to 5 rows on one side of one bed. Image shows plastic tensioner and 6mm tension slat below existing top slat. Also available as single items. Widths available are 53mm and 38mm. Suits Queen, King, Super King and King Single bed sizes.