The BT2 is the correct Xtender.
From 1967 to 1982, Fender basses (both Jazz and Precision) used Schaller BMFL tuning machines. In recent years, many Fender reissue, tribute, and artist models began using the same tuning machine.
They are easily identified by the trapezoid shaped tuner body. For maximum confidence when purchasing, we recommend printing out the 1:1 scale dimensions from our site and comparing them to the peg head.