The product is made of high-quality stainless steel, does not , and can be installed outdoors It can be used in conjunction with door closers to automatically close the door and control the closing sequence Built-in springs, bearings, strengthened and stable; nylon balls, more wear-, smooth and unimpeded Features: smooth, no noise, long service life, control the different order of closing the doors on both sides of the double opening Easy to install and ready to use right away, it effortlessly meets your automatic closing needs., Manufacturer: BgnEhRfL