This circuit is mostly on public footpaths / bridleways, but there is some minor road involved. See SGB 01 ~ Shamley Green Bipedal-motion for details.
This cache is a 450ml clip-lock box.
On the route between SGB 11 and SGB 12, you can pass by A Fine Pair # 73 ~ Shamley Green, which would have been part of this SGB series, if it wasn't a better fit in the Fine Pair series.
SGB 12 itself is a little way up an off-route footpath, you will need to retrace 100m of your path having done it.
Good hunting. You may also be interested in my other caches.