Wall thimble questions

[Dave Tesch]

i need some help with how to install a type b wall thimble. i do not understand how to mount it on the exterior of the siding - am i supposed to cut the siding away anf mount the thimble to the wall under the siding, ir do i mount the thimble over the siding (leaving gaps betwen thimble and siding).the thimble has holes in the flange, am i supposed to fill these? the thimble is a duravent type b thimble.thanks, BTW i am having great difficulty using this forum todau, i cant go back and correct misspelled words, any attempts to changemy post results in even worse errors...never seen this type of thing before, return key wont work, no copy paste, cant retype words etc. thanks

[Thom Sturgill]

Their documentation shows framing sized to support the vent and line up with the holes. I would say that it mounts to the studs or sheathing.

[Dave Tesch]

it looks like this

http://site.fireforless.com/yswimages/simpson-dura-vent-3--duravent-type-b-wall-thimble-3gvwt.jpg

the amount of detail my instructions go into is roughly "mount the thimble"