Door Bell Advice

Hello I want to install a HIkVision doorbell to add to my DS-7761Ni NVR, and have come across two options.
1.DS-KB6003-WIP
2.DB-120A-IW

Having compared the two on spec sheets, it's not obvious what the difference is to compare the two units, and wondered if anyone can assist me please?

Interesting. I just looked at the spec sheet of the DB-120A-IW and I’m not sure how it’s different. Would be interesting to find out

It seems that DB-120A-IW is the HiWatch model and DS-KB6003-WIP the Hikvision model.

Maybe they have the same hardware, but with different firmware?