AUTO METER3204 Mounting Cup

according to description this is Available in several gauge diameters, what diameters ?

Is this for a gauge that’s 2 1/16 or 2 5/8?

Can this be installed with teh gauge already in place? or will it have to be removed and re-routed to allow for the tube to pass through the mount?

Will this work with 2 5/8 tci gauge ? thanks