... 1.made of 100% silicon material 2.Funny DIY lego blocks 3.Keep books from water,dust etc 4.softness promotional ... material, reach to food grade standard 2.Funny design with building blocks silicone cover for books3.Can buy extra slips in different ... and friends4.We have developed 9 standard colors for our building series silicone book: Red, Black, Purple, Green. Yellow, Pink, Blue ...