A No. 4 smoothing plane has a short sole by design. This enables the woodworker to do spot work on sections with irregularities that would be impossible with a longer plane (e.g. a No.5 or No 7). This then creates a smooth surface that should not need sanding.
The plane also has the frog lying directly on the body of the plane. This means the mouth can be easily opened or closed without having to remove the irons. It only takes releasing the two screws at the back of the frog to move it back or forth – this makes setting the desired mouth opening easy, quick and accurate.
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 a review of the Luban No. 4 Bench Plane by guitar maker Gary Rizzolo: