KJN sell their own extrusion and also Bosh Rexroth stuff as well, if you look closely each item will show which is which. I have found that for some of the Bosch stuff can be got cheaper from Hepco ( http://www.hepcomotion.com/en/mcs-ma...m-pg-14-get-31 ) You have to juggle between the two sites doing a bit of maths. KJN also do a whole lot more sizes than you can see on the site ... just email and ask.