The quality of different life expectancy is also different, the key also depends on its copper material, TV or computer generally want to use high-grade phosphorus copper material which sockets. Poor quality copper clad aluminum sockets will oxidize away in a year to two years. If your home is these sockets, I suggest you throw away and re-buy, because that is very unsafe. Bull's is good but dead expensive. If the owner does not want to buy expensive to learn to look at their own, other brands are fine, but the market is full of brands, the quality of Ceng Jianqi. South Boxing King is also good, the quality can be, the price is moderate, more cost-effective, want to know more can go to my Baidu space to see!