GEVEY™ Ultra S for GSM iPhone 4S

Howdy folks.
I'm sure this is the simplest of all questions to ever be asked here, I did try a quick search but couldn't immediately find a simple answer to my simple question.
I have an iphone 4s locked to Sasktel. if I want to use it on a different carrier (lets say rogers for example) I just plug a rogers sim in with the gevey thing and it's good to go? Does the phone number and plan change to whatever is on the rogers sim or do I retain my sasktel plan and number?
thanks.

I'm not sure this is correct forum for this.

In the US, the different carriers use different network mechanisms for cellular, so simply swapping SIMs either doesn't work at all or is very glitchy. A phone sold at Carrier A only works with Carrier A's network. This trickles down to carriers like Verizon who don't use SIMs.

You would need to know if the two carriers you want to switch between use compatible networks.

If the phone is locked. It's locked to that carrier. You need to unlock it to make it "Open Line".
Open Line phones can use any carriers. With the unlocking thing, I don't thinks it's legal but there are phones that are open line already.

I don't think the Gevey works anymore, but if you already have it you can give it a shot. Worse thing that could happen is that you brick the phone and Sasktel charges you to fix it.