It will need 4 plastic injection molds to make handle extender and 1 two-color mold or 2 single-color molds to make faucet extender. All molds should be high-precise to make sure that all parts are well-assembled, especially the faucet part. Two different materials have different shrinkage, it needs excellent molds and experienced test engineers to produce beautiful products. Besides, it is also important to have no tips or flash to scratch customers.