Has anybody had any experience of THIS type of clip?

If so what size do you use. Having measured my top & bottom hoses I get calliper readings of the diameter over the high point between 47.76 & 51.6mm
Rad side is the larger. What size do I need? I emailed Westfield but after a week no answer. Any size charts seem confusing to me.
Sorry for question which I suspect has an obvious answer.


4/4 Ivory 4.1:1 axle, Mercedes A200 AMG