This is a Chenelec B-1033 0.15uF 12kVpk capacitor.
We have a bunch of these, and they all measure within 0.07uF of the nominal value on our cap meter.
We don't have a way right now to measure esr, unfortunately.

We're a surplus store, and we aren't experts with most of this stuff;  we don't make any guarantees beyond what's stated in the listing & pictures.
Please to contact us with any questions!