| 摘要 |
An apparatus that includes a first frame and a second frame coupleable to the first frame. The first frame includes an inner edge, an outer edge, and a base extending between the edges. The second frame includes an inner edge, an outer edge, a base extending between the edges, and a sidewall extending substantially perpendicularly outward from the inner edge. The sidewall includes a lip portion that extends beyond the first frame's base once the first frame is coupled to the second frame and the sidewall is inserted adjacently through the first frame's inner edge. The first frame is coupled to the second frame in at least a first orientation and a second orientation. The lip portion has a first length when coupled in the first orientation and a second length when coupled in the second orientation. The first length is smaller than the second length.
|
