Librem 14 and 15 power brick specifications

What are the specifications for the librem 14 an librem 15 A/C power adapters? (I’ve seen the similar posts in the sidebar, but they don’t really answer the question specifically.) Specifically:

  • what size plug do they have to connect to the laptop?

  • How many volts out?

  • How many amps out?

  • Is the polarity positive center or negative center?

Since these are offered as a seperate purchase from the laptop, I want to see if I have any in my giant bin of computer parts that will do the job.