fixed or ajustable cambelt tentioner?

[mark]

i been looking at the belt tentioners for my 1.8 on shopforparts and its offering me either a fixed or ajustable? the fixed one is about half as much and looks like its not going to break like the last one (the ajustable one made of plastic) are they for different models?
http://www.shop4parts.co.uk/index.cfm/method/catalogue.list/

 

[Dan]

you need both when replacing the cam belt,

i got a qoute for £80 (or around that), which was both tensioners, and cambelt