What is the height of the BUIS?

Can I use regular AR sights?

Thanks in advance

Only if you swap out the front post. The KRISS front sight post is shorter.

Darn, so I'd have to order an entire set...

The rear sight is the same as the AR. You might be able to get a replacement front sight post and shorten it... unless somebody could tell us with certainty what the measurement is to possibly order one to spec. Are you in need of sights for your Vector or just thinking of different options?

Just thinking of different options. But, I'm confused that the rear is the standard AR sight, but the front is shorter? Wouldn't that throw off the sight alignment?

The front post is slightly shorter to deal with the .45ACP versus the .223/5.56 capabilities. That's what I was told by a KRISS USA 'smith. I didn't think to ask him at the time for exactly what the height difference is. So far we have not been able to get a member with digital calipers to take an actual reading for us. (Previous threads.)