They are quite remarkable. They do indeed get their name from the similarity to weed strimmers, but are made of nylon with a Kevlar core. Apparently they were first invented for rockabilly 'slapping'. One curious aspect of them is the range of colours - I ordered them in 'plain', which means I can see the string core through the outer. Another odd thing is, unlike many double-bass and bass guitar sets, that they define the string sizes - the set I got is 95-155, I think.

The price is incredible - a single decent double-bass string in the UK is £25 or so, and I think these were mailed to me from the States for thirty dollars.

However, I had heard that they were prone to stretching and lost their intonation. I fitted my set yesterday, and they seemed to hold their tuning overnight. They're certainly very comfortable to play... like a heavy set of classical guitar strings. I'll be taking my bass to a ceilidh rehearsal session on Monday (Occasional Ceilidh Band, Norfolk, England) and we'll see how they stand up.

Meanwhile, you can find them at slaphappyweedwackers.com - they're in a place called Austin, MN.

Cheers
-Cappuccino, Norfolk, UK