Brand: SPA Design Racing Products
This push-in type Y fitting is designed for use with 8mm (5/16") Dekabon Tubing (Part No. 2456-.312).  It will not work properly with bare aluminum tubing.  Sold individually.  
This size tubing is used in SPA FIA18 AFFF (2018-2023) fire systems and current SPA / Protrust FIA Extreme Novec (2023 and later) fire systems.  New fire systems are shipped with Tee fittings, but those can be replaced with these Y-shaped fittings without affecting the homologation.    
 
Note: SPA Halon and older SPA AFFF fire systems (prior to 2018) used 6mm (1/4") tubing, not 8mm.  We stock the SPA Push-In Tee Fitting for 6mm (1/4") Dekabon Tubing (Part No. 2448) for those older systems as well.