OPEK AT-7516 - UHF PL-259 SO-239 Coaxial Lightning Arrestor
The Opek A7516 Lightning Arrestor is an "air gap" arrestor. Although it is okay for tube sets it is not recommended for solid-state rigs; however, if you are on a budget, this device is a better than doing nothing. As with all lightning protection devices... you must connect it to an earth ground with a thick ground wire for it to work correctly. It can be used for receive, or transmit up to 100 watts.
OPEK Communications also makes a quality line of Gas-ARC surge protectors / lightning arrestors for improved protection.