This is reed spline, used to hold cane webbing in the groove on cane chairs. Please use the chart to determine the size you need. The spline comes in 6 foot long pieces, so a quantity of 1 will get you one 6' long piece of the size you choose. A quantity of 2 will get you 12', a quantity of 3 will get you 18', a quantity of 4 will get you 24' and so on. Please make sure to choose the correct quantity and size you need. If your chair has holes drilled in the seat frame, you do not need spline.