Bristan Artisan Professional AR SNKPRO C O-Ring Kit 1425R (not for the EASY FIT model). If your Tap is dripping where the Spout meets the Base.  Here is our Guide: How to change a Kitchen Tap O Ring Kit  Guide.  Not for Easyfit model.

Here is the link to all our  Bristan Artisan Kitchen Tap Parts.

Note on the Grub screw included with the O Ring Kit: The grub screw takes a 2.5mm allen key. Please retain your existing grub screw in case it is an earlier version in which case you will need to use your existing grub screw.  This O Ring Kit covers several different UK Kitchen Taps so you might not require all the O Rings provided in the Kit.