The 3.5 inch spool kit makes it easier to store and hold extra cording, ropes, and string. Unwind your cording of choice to the desired length without having to worry about it becoming tangled. Assembling the kit is simple with four easy to follow steps for putting together the two spool ends, spool core, 2 spool plugs, and for a more durable hold, you can use the glue provided.