1.1 This specification describes the properties of devices or assemblies suitable for use as flexible transition couplings, hereinafter referred to as couplings, for underground drainage and sewer piping systems. 1.2 Cou This specification describes the properties of devices or assemblies suitable for use as flexible transition couplings for underground drainage and sewer piping systems. Couplings that may include bushings or inserts, and meet the requirements of this