Saphena Anti-Embolism Below the Knee Stockings Saphena anti-embolism stockings is a product you can trust when it comes to helping reduce the threat of blood clots forming in your legs. Saphena anti-embolism stockings provide pressure to force blood back towards the heart with graduated compression which is strongest at the ankle and reduces further up the leg. By compressing the surface veins arteries and muscles they force circulating blood through narrower channels. As a result, the arterial pressure is increased which causes more blood to return to the heart and less blood to pool in the feet. Saphena is a Class 1 medical device and conforms to the latest European Standards for graduated compression and also complies with the Medical Device Directive. The compression profile of 18mmHg (ankle) and 14mmHg (calf) is in line with British Standard 7672:1993. This is the below the knee version but these socks are also available in a thigh-high version. This below the knee version is preferable compared to the thigh-high version if you are looking to avoid constriction at the thigh. This product is available in 4 sizes including small standard large and x-large. They come in green they are machine washable and made in the United Kingdom. The material composition is 85% nylon 15% elastane.