I got Brain Freezer TPU Strap for Mi Band 2 & HRX from Amazon India for Rs. 210.
The packaging of the band was ordinary and like a roadside product. The band itself is made of rubber which is on harder side compared to the original Mi Band strap.
The design looks good but it is not user friendly. The original Mi band has the strap pin going in the hole from outside, so it is easy to wear and set the band size. In the Brain Freezer one, one side of the strap goes inside and you have to put your finger inside the strap to fix it in position. It is very difficult, impractical and impossible to do if you wear the strap tightly.
Also the product I got did not even have the plastic pin which goes inside the hole to fix the band size after wearing. I could have asked for a replacement but I will ask for a refund.
If you put on the band every day then it is not a good buy. If you wear it for weeks then you might like it.
Otherwise do not buy.