I'm after a pair of Flexible Tap Tails for a monoblock kitchen sink lever
tap. The question I have is that I have found 2 different types of sizes on
sale at either Screwfix.com or Toolstation.com, these are 15mm x 10mm and
15mm x 12mm.

http://www.screwfix.com/app/sfd/cat/...87261&id=91351
http://www.toolstation.com/shop/Plum...ors/d20/sd2807


Would anybody know how the measurement is made for the actual connector to
the tap? If measuring the diametre of the thread then it's 12mm where I
would require a 15mm x 12mm but i'm not entirely sure how it is done as the
tap purchased from MFI has no specs.

My local plumbers merchants weren't too helpful so would appreciate any
tips on the above.

Thanks

P