The Delta Levelling System levelling clips are available in a variety of thicknesses to enable precise fixing of 1mm, 1.5mm, 2mm and 3mm paving. They are also designed for different paving thicknesses, namely 3 -12 mm, 6-15 mm or 11-20 mm. A pack of 100 pieces contains clips for 6 to 15 mm thick tiles. The clips need to be constantly replenished because they break during laying and remain under the paving. The clips are made of durable plastic.