Hộp móc len tham số (Parametric Crocheting Hook Box)

To modify the box dimensions, choose “Modify”/“Change Parameters”.

Here you can enter your desired inner width, length and height. 

If you change the width, you'll have to shorten or lengthen the clips, but that's easy - just select the face at the end of it and extrude it to the desired length of the clip holder, which is the inner width of the box +1.5 mm.