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 11 to 20 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.