Here is a quote from Auto Refrigerants.com (and what I was told yesterday). This regarding their colder industrial variant,.....I'll check with ES to see if it applies to the Regular ES-12a

Introducing our newer "Industrial 12a" in the cans. (pictured here) The picture shows the original 8 oz. cans but these are the new 6 oz. cans. Each 6 oz.can of it is equivalent to 18 oz./Freon or 16 oz./134a. It is even colder than the regular ES-12a! It is a slightly higher pressure product and may be charged into a medium vac, a shallow vac or even zero vac. That makes it virtually mistake-proof, unless you over-charge the system. If you think the regular formula is cold (and it most certainly is), this Industrial 12a will amaze and delight.