FESTO 153160 QSS-10 PUSH-IN BULKHEAD CONNECTOR - SUPPLIED IN PACK OF 10: Amazon.com: Industrial & Scientific
6mm x G1/4'' Push-in Fitting with Female Threads Brass/PA 66 NBR Bulkhead [2 Pieces] | Tameson.com
QSS-8-F Festo | Festo QSS Series Bulkhead Tube-to-Tube Adaptor, Push In 8 mm to Push In 8 mm, Tube-to-Tube Connection Style, 130642 | 121-5956 | RS Components
QSS-6 Festo | Festo QSS Series Bulkhead Tube-to-Tube Adaptor, Push In 6 mm to Push In 6 mm, Tube-to-Tube Connection Style, 153158 | 121-5954 | RS Components