I advise to double check size with the seller before committing. see: https://www.ebay.it/itm/364735402883 Most of the 1940s/50s seat collars are by Magistroni, and /or branded Bianchi, Olmo, Ideor and Legnano. Search ebay.it and enter 'collarino morsetto regisella e'poca' to see other choices...