SS-402-1
LOT OF 10 NEW NO BOX! SWAGELOK 1/4" TUBE OD NUTS SS-402-1
You will see that the F3SN-A0307P25-D-04 F3SN-A0307P25-L-04 has a 0.2-second startup delay.
Swagelok Nut 1/4" Tube Fitting, SS-402-1, SS4021, LOT OF 16, SHIPSAMEDAY #ZM10
What I appreciate is the lightweight yet strong metal design.