In most cases, we suggest fusing (soldering) rings together, especially our halo sets.
 
The main advantage of this is that it increases the longevity of the rings. When rings are rubbing against each other it creates a sandpaper effect, which can eventually lead to costly repairs and sometimes loss of side stones.
 
Fusing also ensures that the stones are lined up and the wearer doesn't have to keep adjusting the rings as they move on your finger. 
 
Bear in mind that a fused set would need to be sized a bit larger than your normal ring size - due to the overall thickness of all the bands together.  A rule of thumb is sizing the set 1/4 size (0.25) larger than your normal ring size. 
 
The only time we suggest not fusing rings together is if someone wants to wear the rings individually, as the fusing process is extremely hard to undo and could damage the rings.  If you are unsure about fusing your rings, plastic ring connectors can be found on sites like Amazon. 
 
This listing is for 2 or 3 rings.