... bottom is groove. Waterproof,fire retarding, wearing easyand nice pvc fence panelsprinted pvc panel1)Fetures:wearing resistance,waterproof,flame retarding,aging resistance,smoothness ... :5.5mm,6.0mm,7.5mm,8.5mm,9.0mm5)PVC%:40%,45%,50%6)Surface: common glossy, high glossy, matt ... colors can be supply by customers and made by us. pvc fence panels