Chinese Thermostatic valve heads.

[ringpulled1]

Hello, does anyone understand the instruction on attached photo? Or what is your interpretation of  it.  These are the low cost Chinese valve heads sold in packs of 4 or 6 for approx £9 - £16. 

[redwick1]

I don't think I would be buying something like that off a seller from China on ebay.

My interpretation would be that the item has to be mounted in a horizontal position not upright.

[red_magpie]

I think the pictures are simply telling you to align the base fitting correctly with the splines, and to mount the body of the vave horizontally not vertically.

I hope they work for you, but provided you don't have to make any changes to the plumbing they will only take minutes to fit or remove so if necessary you could easily replace them with known brand products. But you won't get them in packs of four for less than a tenner!