It is retailing for JP¥3,110 (JP¥2,880 before tax), but if you spend more than JP¥5,000, it is tax-free. On top of that, if you pay by VISA credit card, you get an additional 5% discount.
After everything, I paid JP¥2,736 (S$34) for it.
It is made of polycarbonate and is only 1mm in thickness.
Because it is thin, it will partially work with the official Apple Smart Cover.
The reason it is not 100% compatible with the Apple Smart Cover, is because the case is lacking a cut-out area for the magnets of the Smart Cover. Hence, the strength of the magnets is not strong enough to hold the iPad Pro up using the Smart Cover.
If you are just using the Smart Cover to protect the display of your iPad Pro and not using it as a stand, then you have nothing to worry about.
I think right now, it is tough to find a clear back cover for the 10.5″ iPad Pro as it is very new. I have not seen any being sold in Singapore yet.