PrimoChill Rigid Ghost Compression Fittings are finally here after months of R & D and testing! PrimoChill??s goal was to provide the user the simplest possible method to install Rigid tubing into your system. The use of one oring and a meticulously designed nickel plated G 1/4 base fitting allows the user to install rigid tubing without the need of complex tools. With the addition of the Aluminum cap, a perfectly balanced amount of compression is applied to the rigid tube which prevents the cracking of fragile acrylic yet still provides enough pressure to eliminate the escape of fluid.