This is either the wrong picture or the wrong model#/description. The picture is of the RM-15/2 which is a 2 pack of the CUTTING MATS that mount in the trimmer. K-M51 would be a 2 pack of blades like at https://www.mybinding.com/carl-replacement-perforating-scoring-set.html and $2.99 would be a great price. (I’m guessing the picture is wrong because they borrow from Amazon and they got it wrong too…) Though the picture does not match the description I would buy these and if they are not what is described SEND THEM BACK…