When the set time is up, it will deflate automatically, then the exposure is finished. Please cut off the power supply. It has the same exposure effect with the exposure unit exposed of iodine gallium light. Even if its exposing time is a little longer, but because of its small volume, light weight, low cost and easy transportation, which is much fit for small business and family workshop for making screens with high precision.The vacuum pumping area (sizes of the rubber blanket) is 19.723.6 (5060cm), but the optimum screen exposing size is within 15.719.71.6 (40504cm) by the outer sizes. Exposure area: 19.723.6 (5060cm) Optimum screen exposing size is within 15.719.71.6 (40504cm) by the outer sizes. Vacuum Time Setting Range: 0-999s. Exposure Time Setting Range: 0-999s. Please feel free to contact with us if you have any question. The item "50cmx60cm (20x24) Precise Vacuum UV Exposure Unit Screen Printing Machine J" is in sale since Monday, August 14, 2017. This item is in the category "Business, Office & Industrial\Printing & Graphic Arts\Screen/Speciality Printing". The seller is "mywelllife" and is located in CN,CN. This item can be shipped to all countries in Europe, all countries in continental Asia, United States, Canada, Australia.