'mater - the speedos do have a spring in them, but the magnet is what drives them .... and note magnets don't "weaken with age", that's why they're called permanent magnets, dirt buildup will be the problem

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot