According to their names, 3157 looks like 3157NA.

Do you know what’s different between 3157 and 3157NA? if not, I would like to give you answer as below.

3157 bulb is clear glass and 3157NA is amber or yellow painting glass.

The luminous of 3157 and 3157NA is very different.

3157 is 475lm, but 3157NA shall be 250lm, so 3157 shall be much more brighter than 3157NA.