LED pulse on Pulse Sleeve?

I'm a huge Roger lover and follower and never really pay much attention to the specifics of Post waters Floyd...
But, last night whilst reading my MOJO Special Edition on Floyd and they said something about the Pulse sliding cover...That it has a LED (what is that?) that pulses like a human heart. They wern't talking about the book with the CD's in it, they were talkinga bout the outside sleeve with the eye on it.
Does anyone have a copy that beats or whatever it's supposed to do? Mine doesn't beat and I'm wondering if anyone else's copy of Pulse does?
It says there's something in the cover that makes it do that called an LED...I'm confused! LOL
Help!

the first ones in production had led lights on the spine, but not ones that are made now. led lights are the ones with a bunch of little bulbs in them, instead of having one bigger one.

I believe LED stands for light emitting diode

You're right, Wilt.

The original CD sleeve included a small bulb and battery assembly which flashes at approximately heartbeat-rate.

The battery lasts for about 3 or 4 years. I replaced the battery in mine about 3 years ago and it's still going strong.

Read this RWG:

http://www.pinkfloydfan.net/t1268.html

Me too, it's flashing away at me right now.

Yup.... pulsing away....

never changed the battery in mine, it's still goin strong

Well mine does blink;though faintly.

Mine is still blinking, but barely visible. I'm guessing within a month it will be gone.

This second set of batteries lasted just over 4 years.

SO ours is around the same time?

Mine has the light. I bought it the week it was issued.
What would be really impressive is if any one bought the 4 L.P. box set of Pulse?