3 Double End Clock Keys. This is a new set of 3 double ended clock keys. You receive: One size 4 & 000 clock key with a 1.75 mm hole and a 3.25 mm hole. One size 5 & 000 clock key with a 1.95 mm hole and a 3.50 mm hole. One size 5 & 00 clock key with a 2.00 mm hole and a 3.50 mm holeWe work hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.