STS are one of the best after market accessories I know of. I've got them on my Allegiances, my Guardian, and my boy's Jaguar. They quiet the sting down considerably, to the point that I've removed the factory string silencers on my Allegiances as they start to shoot apart. They are also remarkably effective at removing vibration without the need for a heavy stabilizer. Finally, as noted above, one the great attributes is stopping string slap. I'm a big fan of the technology! Just look what Hoyt has added to their new bows! Why do you think they did it.?