WOOD LOCK (external analgesic,25 ml) Wood Lock is an external analgesic medicated oil for the relief of minor aches, pains of muscles, joints associated with the backache, arthritis and strains. It is extremely effect to combine with the thermopenetration method. One bottle is net weight at 50ml in a glass jar. Drug facts: Camphor 10% Methol 16% Methyl salicylate 50% For external use only.