The Ventline V123 is an obsolete part, but the good news is that it's a standard 14" x 14" roof vent, so you've really got unlimited options. I recommend using the Ventline E-Z Lift Ventadome Trailer Roof Vent w/ 12V Fan - Manual Lift - Smoke - Canada Approved # V3094-603-00C, which is a manual lift vent that will fit in your roof opening. If you'd like to upgrade to a powered lift vent, the Ventline Ventadome Roof Vent w/ 12V Fan - Powered Lift - 14-1/4" x 14-1/4" - Smoke # V2119-603-00... view full answer...