Sinavoshop Reviews 

Product does not work. Don't be scammed. I bought 2 pairs. They're useless.
No refund? This is an absolute scam.
DO NOT BUY
DO NOT BUY
I bought two pairs, big mistake.
Did not want to refund. They claim it was on sale. The product is always on sale, means no refund always
Fake reviews
The reviewes posted on their web site are filtered and fake. Do not believe any of them. I sent my review and did not get published.

Absolutely awful product and customer service. This product is not as advertised, it doesn’t even stay on the leg never mind help “spring it back up to help with knee pain” when customer service was contacted i was told “sorry no refunds or returns for on sale items” on sale? For $80? This product isn’t worth $8. They can have their “quality product” back i just want a refund. This company is a bunch of scammers! Looking into what i can do with the BBB.

Ordered 2 pair of the PowerKnee Joint Supports. Although they charged me for the purchase the minute the order processed, I did not receive them for over 7 weeks. Within 3 days I contacted them to tell them that the product was unsatisfactory. The springs were too stiff, causing the top half to dig into the backs of my thighs. I asked to return them. I was flatly told "No Returns. No Refunds." Subsequently I learned that they charged me 3 times over for the product. You can get the same thing on ebay for less then $25, and they claimed the reason they wouldn't take them back was because they were "....on sale" for over $75! I did not see any reference to their return/refund policy during the ordering process, but they provided a link to it when they answered my request to return the product. Doesn't seem quite right, does it? This is a rip-off company offering an overpriced product that does NOT work as advertised. Stay away! P.S. How can you have a 3-star rating when all 3 reviews are 1-star? Do them simply add them up?!

Ordered a knee product. Realised it was not exactly s I understood it to be, almost immediately requested a cancellation. This was declined and then I asked them to confirm and address and refund. No chance. Have it open with paypal. Do no engage with this company.

I was looking at their products as they look interesting. But their website is full of fake testimonials. They put "as seen on" "kickstarter, cnet, theverge etc". This is total lie. Their products were never featured or seen on any of these platforms. If they dont have a business address, most likely its just a chinese company with fake reviews sending you goods from China.
I would be cautious before purchasing from them