The original rack that comes with the NO12 is not a good design, It is too low not allowing good airflow particularly on full power with larger cooking pots. The original rack also traps the flame in the centre creating a hot spot in the middle of your pan. Please check out this great video from a customer and tester for this rack.
https://youtu.be/EadTJ3OtKcg?si=zGsci8m4N-QTmvim
This is now the SMS finalised version with modifications noted and works great, It is now the same height as the burner case so large pots ( larger than the burner case) can be used without the need for trivet rings or spacers. It does not interfere with the closing of the case and is the largest rack that will fit without modification. It's what the manufacturer should have made for this stove as its just better in every respect than the original. Cook more efficiently and with better results vs the old rack.
Made in the UK from 304 stainless steel.