Make one measurement and you have it's opposite immediately! It's an easy- to- use, accurate way to size lids for pots. You can also make a lid for an already fired pot, by reassembling the wing nut and screw in the 12-1/2% hole. This way your lid will shrink to fit the pot.
 
The Lid Master is available in two different sizes:
Lid Master (Max capacity 11" wide)
Large Lid Master (Max capacity 20" wide)