I have one, uses Klotz cable.
Bit of a funny story.....
About 2yrs ago I picked up what I thought was a cheap
"Neutrik" guitar cable from Maplin's bargain bin. When I got it home I found that 1) it
was a speaker cable and 2)it was clearly not a genuine Neutrik product.
contacted Neutrik who were very pleased that I had and sent me a 5mtr complimentory silent
plug lead! Maplin apologized and offered a refund but in truth as speaker cable the "copy"
was fine and I had a good result anyway!
The silent plugs use a reed switch
AFAIK and are guaranteed 10,000 insertions?