Could some one explain to me what an invector choke is. I'm considering getting a new shot gun and I see a number of the shotguns have this type of choke. I'm considering the Browning Gold or the Winchester X2.

its just the name of browning/winchester choke tubes. invector + is aobut 1/2 inch longer than standard invector. get the gold i have one and i love it

Invector Plus chokes go in a barrel that is overbored. Regular Invector barrels are not.