Does the ZEALOT B28 have active noise cancelling?

Yes. It is sold as an ANC headphone, so it actively reduces ambient noise rather than only passive isolation from the ear cups.

Can I wear the ZEALOT B28 in the rain or at the gym?

It carries an IPX-7 water-resistance rating, which covers immersion in water for a short time under test conditions. That makes it more tolerant of sweat and rain than most over-ear headphones.

How heavy is it for long wear?

It weighs 318 g. That is heavier than many over-ear rivals, so long sessions may feel tiring for some listeners.

What Bluetooth version does it use?

Bluetooth 5.0 with EDR, with a stated transmission distance of up to 10 m.

Does it have a microphone for calls?

Yes. A built-in microphone is included for voice calls and online meetings.

The listing does not detail the accessories. Expect the headphone itself and a charging cable; check the box contents before buying if a carry case matters to you.