I have a typical kitchen tap mixer unit long spout paddle handles either side. Saw it in wickes under Sienna Mono Mixer 207012 but no doubt sold in loads of places. Had this for about 2 years. Problem is its started dripping and I can find no way to get at the cartridge (Cold water) to replace or clean. There are no grub screws visible. I cannot force the "spindle covers" up indeed they seem part of the paddles (my term for the on off levers) Dont want to lever too hard in case......tried gripping covers with protected wrench but just slips..