Mari - The name of them is 'Horse Whisper'. I think they stopped doing that style completely now, they do a full shoe that is similar in style if you ever want a full shoe.
But have a look on ebay - you can get them brand new or very very good condition.
Also look instore, cos they knock the prices right down when the range has been discontinued
My mum got some for £15 (rrp £50+)