This is made to snap into 20 mm X 20 mm aluminum extrusions and hold wires. You can increase the length to make it more stable and also cover more of the wires. I would consider the shown model the shortest u would want to use. It becomes much more stable at about 4 times that length.
EDIT: I have added options for longer lengths. Each of the file names has a numerical suffix to indicate length. Each suffix is a 3 place decimal without the decimal point. EXAMPLE 625 is actually .625" where 3250 is 3.250" and 1000 is 1". I hope this is helpful. The shortest one is all I had up here at first and it is the most unstable of the lengths. If you use ribbon cable try to roll it up so it will apply a slight outward pressure as well as keep the center open for additional wires. I have not yet tried the longer ones so they may be a problem printing without a skirt on the base for bed adhesion.