The well know PL 259 plug (also known as UHF plug) is the most used connector for shortwave purposes. It is very easy to mount and less costly than other connectors. For outdoor use it has one disadvantage: it is not water tight! The coax becomes soaked with water, with signal loss as result. Silicone rubber can protect the connection, but it is very difficult to unscrew the connection later. Besides that, many types of self-amalgamating rubber tapes are not UV light resistant: in full sunlight they become brittle and than they can protect the connection not longer from moisture. A handy and easy solution is the RF Systems RS - 1 sleeve. This sleeve, made of UV resistant flexible plastic, is pushed over the connector and protects the cable and connector against moisture. The RS - 1 sleeve can be used on thin RG 58/u as well as on thick, RG 213 type coaxial cables.