I rarely write product reviews, but I feel like I should warn others about purchasing and using this product. I have had success using this antennae booster on my feature phone (aka dumb phone), giving me an extra bar. There were several occasions when I was able to make calls with zero bars. ZERO!So after getting my HTC Thunderbolt from Verizon, I thought I'll give this booster another try and see if it'll enhance my reception. Instead, it killed data reception. I lost 4G and even 3G connection. I should've known not to mess with the internal antennae of the phone. Once I peeled off the booster, my 4G was fine again! Buyers/Users beware!