EK-Quantum Torque Compression Ring 6-Pack HDC 12 - Blue is a premium locking ring made for the EK-Quantum Torque HDC 12 series fittings. It is not a stand-alone product, requiring an existing Torque fitting's barb.

EK-Quantum Torque Compression Ring 6-Pack STC 13 - Blue is a premium locking ring made for the EK-Quantum Torque STC 10/13 series fittings. It is not a stand-alone product, requiring an existing Torque fitting's barb.

EK-Quantum Torque Compression Ring 6-Pack HDC 16 - Red is a premium locking ring made for the EK-Quantum Torque HDC 16 series fittings. It is not a stand-alone product, requiring an existing Torque fitting's barb.

EK-Quantum Torque Compression Ring 6-Pack STC 16 - Blue is a premium locking ring made for the EK-Quantum Torque STC 10/16 and 12/16 series fittings. It is not a stand-alone product, requiring an existing Torque fitting's barb.

EK-Quantum Torque Compression Ring 6-Pack HDC 14 - Blue is a premium locking ring made for the EK-Quantum Torque HDC 14 series fittings. It is not a stand-alone product, requiring an existing Torque fitting's barb.

EK-Quantum Torque 6-Pack HDC 16 - Blue Special Edition is a fitting multipack containing six Special Edition Red EK-Quantum Torque HDC fittings. These are EK's premium 16mm hard-tube compression fittings designed for use with solid tubing such as Acrylic and PETG. They come with red compression rings and nickel-plated aesthetic rings, which can be changed for another color if the user prefers to. Different color aesthetic rings are sold separately. The fitting barb comes in a satin black finish. They have a non-intrusive, yet striking look, and have NO added branding at all. To make sure they are undamaged in transport, they are packed in a box cushioned in black foam.