supply of bellows set consisting of 1 no. of supply air bellow, 2 nos.offresh bellows and 2 nos. of return air bellow ducts as per icf drg. no. icf/sk3-7-6-072 (latest) type-i. the bellows shall be conforming to rdso specification no.rdso/pe/spec/ac-0197-2020(rev-0).