Which companies have the lowest beta?

Could you please elaborate on which companies specifically are known to have the lowest beta in the market? Beta is a measure of volatility relative to the overall market, so identifying those with low beta could be beneficial for investors seeking stability. Are there any particular industries or sectors where these low-beta companies tend to cluster? Additionally, what factors contribute to a company having a low beta, and how do investors typically approach selecting these types of stocks for their portfolios?