The Parts Place description on Ebay:
New factory hood tach now available from The Parts Place. Made in the USA just like original GM, not like the cheap repros out there. Don't confuse our tach with the others out there that have copied our white outer shell. Back lit number/pointer design. Pointer will accept factory GM tach harness; all others have a generic harness. Also included - the factory harness and installation instructions. Also accept factory heater vacuum hose to tach, included in this auction.*
Competitors don't have backlit pointer design, making ours superior to the others out there.
A few quality points with our tach:
1) Has clear glass lens (not plastic that will discolor or scratch)
2) Accepts factory GM tach harness (not generic universal like the competitors)
3) Top and bottom are screwed together like factory (not silicone glued together like the competitors)
4) 100% like original in fit and finish
5) Can be connected to the dash light to be dimmed
6) Made in the USA with all new parts