Pump Up Fizz Keepers

[sprayer]

A few years ago you used to be able to buy a pump up bottle top that fitted most large soft drink bottles, it replaced the original cap and once screwed on a few pumps of the plunger on the top of the unit kept the fizz in the bottle, they used to be available in Tesco's but I have looked everywhere for them as my two have now seen better days, does anyone know where I can purchase
these pumps from?

[friedgreentomato]

ebay

http://www.ebay.co.uk/itm/PUMP-CAP-FIZZ-KEEPER-FOR-1L-1-5L-2L-BOTTLES-RED-BNEW-/300868578292?pt=UK_Babay_Baby_Feeding_Cups_Dishes_Cutlery_LE&hash=item460d2a2bf4#ht_1046wt_950

[society]

Does this really keep fizzy drinks 'up' and 'alive'?

[sprayer]

Thanks friedgreentomato that is exactly what I am looking for, and yes they do work!