Connect 3/8" tubing to 3/8" tubes on a 90 degree turn with the three eighths by three eighths elbow.

Connect two 1/2" tubes in perpendicular direction with the half by half coupling

Connect 3/4" tubing to 1/2" tubes at a 90 degree angle with the three quarters by half inch elbow.

Connect 3/4" tubing to 3/4" tubes at a 90 degree angle with the three quarters by three quarters elbow.