... used or together with other bases 2,Easy to stack,better wind resistance 3,Unbelievable low cost ... resistance3,lower cost,high performance-price ratio4,Easy to stack,sure to reduce your shipping cost PRODUCT DETAILS PRODUCT ... MATERIALMade by HDPE,UV resistant. Features1)Perfectly stacked to keep the base stable in the wind2)Much lower ... design water tank for flying banner/easy to be stacked