A 1 meter long knitted reactor coil with 0.5mm ID has a volume of 196µl. Therefore you would need 1.9 meter long coil.
As we do not offer a reaction coil with such length needed for 375µl volume, I suggest you purchase 8 meters of PTFE tubing with 0.2 mm ID (MTC catalog number 49210-20) and make a coil from the tubing.
Click HERE to calculate tubing or column volume from dimensions. Click HERE for PTFE tubing ordering information and pictures.