Antennas are usually attached to a metal pipe or mast using a type of mounting bracket. Small antennas, like 434 MHz Yagis, all omni antennas, and 3- to 5- element Yagis for the 150-166 MHz band can be butt-mounted using a bracket which fits onto one end of the boom. Large antennas, like 6- to 9- element Yagis for the 150-166 MHz band need to be mounted along their mid-point to even out the lateral force on the mast. Larger antenna can be butt-mounted, but usually require support wires attached to the mid or end point of the antenna.