Key component of the nexin-dynein regulatory complex (N-DRC), essential for N-DRC integrity. Involved in the regulation of flagellar motility (By similarity). Involved in sperm motility. Required for the sperm to enter in the coiled storage seminal receptacle (SR) tubule (PubMed:21289096). Detected as regular puncta along the flagellum. Testis-specific (at protein level). Belongs to the DRC7 family.