There are many varieties and specifications of PVC trunking. In terms of models, there are: PVC-20 series, PVC-25 series, PVC-25F series, PVC-30 series, PVC-40 series, PVC-40Q series, etc.In terms of specifications, there are: 20mm*12mm, 25mm*12.5mm, 25mm*25mm, 30mm*15mm, 40mm*20mm, etc.