i have used one for a few years. it isareally bright sight.i just bougt a new bow and was going to one on but saw the viper sight at the harrisburg show and was impessed.you can replace the fiber if you break one. and the fibers were really durable. he was tieing a fiber strain into knotts. i would check out the viper but i dont think you would be disappointed with the sidewinder!!!!!!!!!!!!