Notice:Dear friends, thank you very much for liking our products. The image you have chosen is the product you have received. please refer to the webpage instructions for details. All products are made of molds, so there is a slight error between each product. The error range of each product is 1-3mm.Product description:      Material: Brass, aluminum alloy, silicone resin, stainless steel, acrylic, etc      Weight: 200-700g.      Color: as shown      Size: as shown      Use schedule as belowHow Do Pump Traction Devices Work?       This gentle ,painless stretching causes the cells within the corpora cavernosa to pull away and split.Just like muscle buliding,during the cell healing process,healthy new cells are created,allowing your penis to become larger.And with a bigger corpora cavernosa,your penis can hold more blood,meaning you'll also enjoy bigger and harder erections!  Instructions for useLubricate the inner wall of the cylinder and yourself. Insert your penis into the cylinder. The cylinder should remain firmly pressed against the base of your penis to keep air from escaping.Slowly begin to work the pump. There will be a slight sensation as air is drawn from the cylinder. For beginners, it is important to start this process slowly to avoid discomfort. Remember to press the safety release valve if the vacuum becomes painful. Continue pumping/releasing air until you've found a level of vacuum suitable for you: the penis should look swollen, but should not hurt.Now make sure no air escapes (unless needed) and wait 20 minutes. You may need to pump further during this time to keep an appropriate amount of vacuum in the cylinder.Once the session is complete, you should appear thicker/longer and have heightened sensitivity. These results are effective for 24 hours, but you may experience permanent results through long-term use. We recommend 3-4 sessions per week.   Penis enlargement pump sizesAcrylic Model A1:4.4-22.9cm/1.75-9inch  ;Acrylic Model A2:5.1-22.9cm/2-9inch     Acrylic Model A3:5.7-22.9cm/2.25-9inch ;Acrylic Model A4:6.3-22.9cm/2.5-9inch     Acrylic Model A5:4.4-30.5cm/1.75-12inch ; Acrylic Model A6:5.1-30.5cm/2-12inch     Acrylic Model A7:5.7-30.5cm/2.25-12inch  ; Acrylic Model A8:6.3-30.5cm/2.5-12inch The material is made of environmentally friendly acrylic blocks, which can be used with confidence Pump Instructions:       Nylon Tie Rod, comfort washer, elastic connecting tube Material:       Brass, aluminum alloy, silicone, stainless steel, etc Easy  Release  Connector  Instructions 1.To connect the tubing,press and twist the connector at the end of the tube.       2.When you hear the click,the tubing is fully inserted.       3.To remove,push the metal tab inward and pull the tubing at the base.Youcan remove the tubing and pump while maintaining pressure in the cylinder. Pump Instructions:       Puller, negative pressure gauge, leather tube, acrylic cylinder, silicone gasket Pressing The Black Button Will Release The Air Pressure The acrylic tank comes with a seal switch, after removing the link pipe can still maintain negative pressure.