Avquotes.com recently added RVSM modifications to its online aviation maintenance and refurbishment quote system. The Greer, S.C. company said it currently has 13 service providers on its list with capabilities to perform RVSM modifications on 44 aircraft models. Domestic RVSM airspace is scheduled to go into effect in the U.S. and Canada next January 20. Avquotes said users should allow a minimum of five days to receive quotes, provided by at least three mod shops. Nearly 65 providers of maintenance, refurbishments and modifications are now providing quotes through the Avquotes Web site. The company said there is no charge to request quotes.