Just found this JVC alignment kit. It indicates JL-B44 tonearm effective length is 245mm, 9-5/8". Several places call it a 12" tonearm???
https://www.ebay.com/itm/JVC-JL-B41-B44-B55-B77-QL-5-7-A7-8-10-Y3F-Y5F-Y7-Tonearm-Alignment-Protractor/112624526630?hash=item1a38f1e526:g:LpMAAOSwjShdfjQd
https://www.ebay.com/itm/JVC-JL-B41-B44-B55-B77-QL-5-7-A7-8-10-Y3F-Y5F-Y7-Tonearm-Alignment-Protractor/112624526630?hash=item1a38f1e526:g:LpMAAOSwjShdfjQd