Fortis Ladies Gaiters - Narrow Leg
They are made from cordura fabric it is a nylon fabric with a cotton feel, tightly woven to stop water getting through when pressure is applied. These are built for rugged, durable performance - cordura offers superior abrasion, tear and scuff-resistance. Like the rest of the Fortis range, they are really robust and perfect for beating or picking-up.
They don't have an under-the-foot strap, but do come with eyelets in place should you want to add your own.
I have a 38cm calf and found that these fitted perfectly - they have internal elasticated clips, with a large Velcro panel that seals over the top - giving the perfect fit. I would say that these would fit up to a 41cm calf comfortably - they are designed for a narrow leg and are meant to be tight when worn. They also have a pull-cord round the top of the leg, to add extra tension if required.