You'll receive assembled wooden frame (like on the picture)
All you have to do, is to stretch your canvas over the frame and use a stapler to fix the canvas on the back side of the frame.
That's all :)
5pcs frame set
Size1: 20x30cm x2, 20x40cm x2, 20x50cm x1
Size2: 30x40cm x2, 30x60cm x2, 30x80cm x1
Size3: 40x60cm x2, 40x80cm x2, 40x100cm x1
3pcs frame set
Size1: 20x30cm x3
Size2: 40x60cm x3
Size3: 60x90cm x3