Onpharma Onset Mixing Pen(s). Pens only (cartridges not included; cartridge refills can be ordered directly from Onpharma).

Note: Introductory order (One pen with four cartridges) from Onpharma runs $699.99. Refills run $418 (four -pack of cartridges).

From Onpharma: Each cartridge of Sodium Bicarbonate will buffer approximately 20 injections with the local anesthetic of choice, or approximately 80 injections per 4-pack.