The product has been developed for easy and fast installation in Narrow Clean-Room and congested ceiling space. YB28-Ⅱ has separated Reducer and Nipple from Flexible that is the main part of this product. Firstly, assemble the Reducer to the Bolt coupled to Ceiling Bar and fasten Flexible Slip Nut. In addition, couple the Nipple to the main piping and then fasten the Slip Nut. At this point, it is much better if you use WrE.N.Ch to fasten the Slip Nut. YB28-Ⅱproduct changed and improved demerit of welded all-in-one product. This product is approved by F.M.