Double barbed plastic fitting used to connect two segments of Hydro Logic 3/8 in. (0.375 in ID) DownUnder aeration tubing (Part Nos. HLP DUWT375-100B & HLP DUWT375-500R). Simply insert fitting into two sections of 3/8 in. DownUnder aeration tubing and secure with two HLP stainless steel clamps (Part No. HLP HC375).