FTSE short ETFs

Any suggestions for a liquid short ETF on the FTSE?
Supposedly the better one for short term traders is the ISF is good on the long side.
I'm just planning on trading my pension a few times a year with these ETFs as and when required in up/down cycles.

try the LON:SUK2 proshares x2 short , it's very expensive and pretty illiquid but if only a few times a year then that should be ok