What size pan does this lid fit?

It has a 12-inch diameter, so it is meant for pans with a rim close to 12 inches across, such as large skillets and woks. Measure your pan's inner rim before buying.

Is the handle safe to touch while cooking?

The knob is described as heat resistant, so it can be lifted by hand during normal stovetop cooking. Use a mitt if it has been over high heat or in the oven.

Can I use it in the oven?

The glass is the main body and the knob is heat resistant, but no oven temperature limit is stated. Keep it to stovetop use unless the maker confirms an oven rating.

Does it fit a pot as well as a skillet?

It can cover any round pot or pan with a matching rim, but it sits on top rather than sealing, so it works best for pans of the same diameter.

Wash it by hand in warm soapy water to protect the glass and knob. Avoid sudden temperature changes, such as moving it from a hot burner to cold water.