Wanted: DA/Ultegra 10-speed cassette

Looking for a cassette, ideally the CS6700 12-30. Should be in good condition if not new.

There's a tiagra 12-30 too, perfectly usable just not quite as light.

But does it work with the stupid DA 7800 alu freewheel body? Seems from Sheldon Brown that only DA and Ultegra will work...

I got ultegra 6700. I will check what gear ratio. In good condition

It's 11-28

105 5600 and 6700 10 speed cassettes work for sure on the 7800 freehub, I never actually tried my 12-30 Tiagra on it as I sold the wheels (they were NOS I'd had kicking around for a few years). Sheldon states that 10 speed cassettes work with that freehub, just not 8 or 9 (and for obvious reasons 11), it just state specifically exactly which aside from the obvious 7800/6600/5600.
here's a Tiagra 4600 and a 105 5600 next and the 6700 at the bottom, the splines are different on the Tiagra to the 5600 and the 6700

Nice, thank you Mr. Bump! So, everything Shimano road 10s from 105 up will work. SRAM I know for a fact will not, not sure about other 3rd party manufacturers. What about Shimano mountain cassettes?

Sorry for the late reply, got one of those locally a couple of days ago, but thanks!