The product does exactly as the description claims - converts a Sim to a Micro Sim - in one easy step. Like other reviewers have noted the included instructions are incorrect, but the hole on the bottom shows the correct way to insert your Sim.
Additional benefit: The remaining plastic from your original Sim has a tight enough fit so that it snugly holds your Micro Sim if you for some reason need to use it as a normal Sim, so the two included Sim Adapters are not required.
A final word of caution though. Be careful how you hold it in your hand while cutting a Sim. When enough pressure has been applied to cut out the Micro Sim the skin on your palm may (as happened to me) get pinched.