For those who have a Central Heating with a Grant MAG One magnetized jar fitted (to collect the metal bits on your system over time), this key fits the top drum lid to open it AFTER you've closed the incoming and outgoing water supply of course.

Remember; the system works under pressure! Close the two valves connected to your MAG One, release the pressure with the radiator key, then fit this key to open and maintain the magnetic core that collects metal bits.

DWG attached too for those who want to adjust it.

Designed from scratch via reverse engineering in BricsCAD Pro V21 because I lost the original key...

Reverse Engineered using BricsCAD Pro V21