If I recall correctly, the gray needles are diamond-tipped, instead of
sapphire-tipped.

Diamond needles will wear longer than sapphire needles, but they usually cost
more than sapphire.

Joseph "Tony" Dziedzic

In article , "Ace"
wrote:
Being a new Seeburg owner, what's the difference between the Seeburg
SAPPHIRE (blue) T-needles, and the GRAY T-needles ? I haven't been able to
find any reference in my manuals for my 220 on which pair I should use?
Thanks - Ace