Here are some of the flip covers for the Lenovo ZUK Z1.
1. SDO Designer Leather Genuine Flip Cover for Lenovo ZUK Z1: This black cover is made up of leather. It is available on Amazon India. Price : 245 Rs.
2. RainbowCrafts Flip Cover for Lenovo Zuk Z1: This cover is available in rubber and plastic black. It is available on Flipkart. The price is : Rs. 329. A bit expensive if you ask me compared to other brands with similar product.
3. CoverOn Flip Cover for Lenovo Zuk Z1: The flip cover has the plastic dark body material. Fits perfectly to the device. It is available on Flipkart the price is Rs. 329.
4. eCase Flip Cover for Lenovo Zuk Z1: This flip cover has plastic black body with premium material. Fits good on the device. Available on Flipkart for Rs. 329.
5. Flip Cover for Lenovo ZUK Z1: This cover available on Juxtacart. The look and the feel of the cover is similar to the RainbowCrafts design. It is priced at Rs. 349.
There are few more available on Aliexpress and Ebay but the price is above 350Rs onwards for this model from some sellers.