When you use the 3D Printer a period of time.
You should have many empty and on using spools.
So I design the connector to stack then together.
And use the empty spool to organize my small tool and things.
Connector should print 2 and adhesive together.
Don't need any screw or drill holes in the spool,use the original holes on the spool
ONLY FIT FOR FLUX SPOOL !!!!