supply and installation of bis listed semi automatic stainless steel preve ntive device with ul approved clean gas with auto manual reverse stainless steel v alve nas 400 mar having capacity 04 kgs and made of stainless steel 304 grade with in dian railways logo on each unit and as per specification attached make model off ered nasa 400 mar cm l no 7200017592 is 15683 2018 warranty period 30 months after the date of delivery