I bought it for the great idea of the ribs of the worm hugging every string, thought it would be very efficient.
I still think the idea is great but the designer needs to do the math properly, calculate the required length and strengthen it where it connects to its hooks. I just couldnt get it stretched in the middle and cover the entire width: it simply isnt that stretchable. So, I either had to stretch it too much which quickly caused one of the hooks to tear off I bought several of them, so I kept experimenting, or stretch it too little, leaving the worm loose and not doing its job.
Knowing what I know about it now, I wouldnt buy it for 1/3 of the price. Actually, I wouldnt buy it, period. My second star is only for the idea of the ribbed design.