N.A.T.O. The defensive military alliance formed in 1949 by ten european countries. WARSAW PACT A military alliance formed in 1955 by the Soviet Union Netherlands. Norway.
Tank Rings. Tank rings filled with gravel lift the tank above the surrounding grade. This keeps the tank out of standing water and increases the life of the tank bottom.
Yoke and DIN Regulators Differ in the Location of the O-Ring. A regulator first stage seals to a scuba tank valve by means of an o-ring. DIN and yoke regulators have the o-ring in different locations. Tank valves designed for use with yoke regulators have the o-ring in the tank valve.