V2 Quick Connect, 19mm Male to 90deg 3/4in Barb
V2 Quick Connect fittings are found on many OEM vehicles including BMW, VW, Audi, Lamborghini, Ford, etc. These Radium Engineering fittings are used with many crankcase ventilation and turbo inlet connectors. They are primarily used for air/oil separation catch cans.
MEASUREMENT
No exact measurement from the actual fitting determines the size (in millimeters). The size is the inner diameter of the tube (or hose) that will be installed onto the fitting. Shown below is a 19mm V2 quick connect fitting. NOTE: it is not necessarily the ID or the OD of the fitting. The size will be in between these 2 values.

IMPORTANT: Always lubricate the mating O-rings with a light amount of oil prior to installing.
20-0758 V2 QUICK CONNECT, 19MM MALE TO 10AN MALE STRAIGHT
This adapts a 19mm V2 quick connect female to a 10AN male fitting. It secures directly to many BMW valve covers.
Engine Compatibility
-Audi A4 (2.0L TSI)
-Audi A5 (2.0L TSI)
-Audi A6 (2.0L TSI)
-Audi TT (2.0L TSI)
-BMW 135i/335i/535i/740i (N54)
-BMW 325i/330i/525i/530i/X3/Z3/Z4 (M54)
-Ford Fiesta ST/Focus/Escape/Fusion (1.6L EcoBoost)
-VW Beetle (2.0L TSI)
-VW Golf GTI MK6 (2.0L TSI)
-VW Jetta (2.0L TSI)
-VW Tiguan (2.0L TSI)
*These adapters are compatible with many engines not listed.
Because it is straight, it is perfect for 1st generation BMW B58B30M0 (B58B30A) valve covers that have a horizontal port, as shown below.

Also, compatible with many BMW engines (S52 shown below).

Machined from 6061 billet aluminum. For corrosion protection, they are anodized type-II. Stainless steel bolts are provided for securing the green retainer.