Gradient Sequential Compression Pump w/ 4 Chamber Half Leg Large Sleeves Pair Complete Set. Made in U.S.A. FDA 510(k) Over the Counter Cleared & Registered / OVERLAPPING GARMENT / Quick & Easy to use Connector w/Safety Lock System / Garment Cover Size: Ankle up to 15', Mid-Calf up to 18', Knee up to 20', Circumference Measurement. Gradient Squeezing Compression Mode System (Relief of muscle aches and pains, increase in circulation, simulates kneading and stroking of tissues...) Pressure: 20 ~ 100 mmHg / 60 min Timer & Continuous Mode / Cycle Time: Inflation: 36 seconds / Deflation: 24 seconds / 1st chamber 9 sec - 2nd chamber 7 sec - 1,2nd chamber 2 sec - 3rd chamber 7 sec - 1,2,3rd chamber 2 sec - 4th chamber 7 sec - 1,2,3,4th sec 2 sec - 24 sec deflation all 4 chambers repeat Certificate of Calibration + - 1% Accuracy F.S. / Cytotoxicity Test, Delayed Hypersensitivity / Animal Skin Irritation Test Pass (ISO 10993-, 10) / Electromagnetic Compatibility, Electrical Safety Test Pass /