While attending one of the CITO events after the bringing in of the popular Compass series, three local cachers were admiring the impressive collection of containers that had been brought in and were now available for recycling. We all spotted some old vacuum flasks and someone said "I'm sure we could do something with those" and after a bit of geochat we came up with a plan for the "Flask series", brought to you by TOFFs (The Old Flask Fellas).
This is the Bonus cache but to find out it's location, you will need to visit the three feeder caches and collect some vital information first.
The three feeder caches are:
GCB06D9 Flask series - pencoise's pink top
GCB2DX0 Flask series - Buzio's silver top
GCB0848 Flask series - Tigger's purple top
Each of the above has a single bit of bonus information. Once you have all three, you'll need to use your geo-brain to work out how to enter them into the checker to gain the Bonus co-ordinates.
NOTE: You do need to put some effort into finding this cache as it is pretty much impossible to guess the required answer, so you will need to visit all three feeder caches to gather the required information.
The container you are seeking is, naturally, another flask but DO take note of the attributes and DT rating when you go out looking for it 
The flask is quite heavy and high up so take care when retrieving and replacing
You can validate your puzzle solution with
certitude.