Product Description:
This is Solid Birch FLooring, and the photo shows it B Grade, someone likes the 
natural knots, so it is real and actual face. The A Grade is much smooth, and no 
any defects on surface, and the C Grade is much more natural, there will be more 
live knots, dark grains, color difference, and some dead knots.

Specifications:
1) Flooring trade name birch (betula spp.)
2) Other names: birch
3) Grows in: Northeast China, Russia
4) Characteristics:
    a) Air-dry density: 0.61 - 0.67g/cm3
    b) Fulvous or off-white, fine structure, medium corrosion resistance