ARC series mini-cylinder are designed and produced in accordance with ISO6432 international standards and CETOP RP52P standards. The cylinder bore is from 8mm to 40mm, hereinto the cylinder is with air cushion if the bore sizes below 25mm, which make the cylinder, have a smooth operation and extended product life. As to the bore size above 25mm in normal circumstances there is no buffer, if you need the buffer, please point it out.