At the beginning of the design, PI was considered, and the previous crooked neck design was simplified. The ball handle was retained. The knob also adopted the shape of ball stretching to make the product echo up and down, and the product was made more delicate through two paint embellishments. The overall product continues the design style of D601, round and delicate, and 800 ml of small capacity is just right for one person to drink. Compared with D601, the spout part has also been simplified to make the production efficiency of the product higher.