What is the standard angle block plane used for?
They can be used for planning and squaring the edges of boards, leaving a smooth surface. They can also be used to bevel board edges and doing spot work. With a spare blade honed at a say 38 degrees you can get block plane that works almost as a smoother and an even steeper angle (e.g. 50) gives you a scraper to work is highly figured wood. This makes it an inexpensive way to expand your toolbox.
You can find a quick primer into block planes here.
The Luban brand is manufactured by the Qiangsheng Tool Company, also known as Quangsheng, who are well known for producing very high-quality tools (including the well-regarded Wood River).
Since its market debut, the Luban brand has created a stir with its wonderful combination of high-quality products (at par with established premium brands) and affordable prices.
Below, you can see Qiangsheng Luban Standard Angle Block Plane in action: