b12 injection cleaner Berryman (0116-12PK) B-12 Chemtool Carburetor/Fuel Treatment and Injector such as all Berryman B-12 Chemtool Fuel Injector
Description
Where you receive the injection matters

[12] It is used in pediatric patients with intrinsic cobalamin metabolic diseases, vitamin B 12 -deficient patients with tobacco amblyopia due to cyanide poisoning, and patients with pernicious anemia who have optic neuropathy

Then the subjects were required to report whether the drop contained or did not contain sucrose, by approaching and then licking the left outcome port if the stimulus was water (0%), and the right port if it was sucrose

I was curious but never really got in to it at that point

And yes, you have to stick it in your cat
