The phone OnePlus One A001 is perhaps the best Chinese appliance available. Read the review of A001 this link. However it is not very easy to find capinhas for him. This below is one of the cheap options, In addition to the original case.
The material is good and protects well.
I liked the product, but I ended up preferring a silicone dust cap, which is better for day to day. I leave the link below: