Coupler

* A two-part device called a coupler lets you use 

different decorating tips with the same bag of icing,

creating several designs with the same color and

consistency.

* A coupler (used in piping or plumbing) is a very short length

of pipe or tube,with a socket at one or both ends that allows two 

pipes or tubes to be joined,welded(steel),brazed or soldered(copper,brass,etc.)

together.