Ground Red Pepper - 20,000 Scoville units (1 lb.)

"Red pepper" is today's designation for any ground hot pepper. "Cayenne" is being phased out and heat units - called Scoville units - are how peppers are graded. They come from Pakistan, China, India, Turkey and Mexico.

The pungency of hot pepper is measured in multiples of 100 units, from the bell pepper at zero Scoville units to the Bhut Jolokia(Ghost Chili) at over 1,000,000 Scoville units!

More about the Scoville scale (wikipedia.org)