Aux Drive Belt Tensioner

[chromedome]

Please can someone tell me what aux belt tensioner I need for my Galaxy as GSF list two that fit my vehicle. One is  about £37 and the other £90.

 

I had a new one fitted just under a year ago by an independent. I think is was a Chinese jobby as it's started jumping about again. Only happens when extra load, like a/c, is applied. The alternator pulley is ok as it was replaced with a proper GSF part.

 

Thanks.

[seatkid]

http://www.auto-parts.spb.ru/cat/au/au.mycat?SelPg&t=9jD8Ej8w/BJlMPwStGqUK8dxpTSlacZKBpD8EsdvfCL2MP5tFhL4HvYGugr2EPyb_2OY2MsXbnr3s6/asupmiIy2ehXCbaVQPgtlZW9BRmDa4fV1VGZPd8S1lRNmkOgeY7x0GDBuCkjqsb2I3XTDPGrh7Tuitvm4GNO3oby2r5SaSCozqTsdCRi_u_M_TkYH6XUSBfTetLX8IvtZ6CT8

[chromedome]

http://www.auto-parts.spb.ru/cat/au/au.mycat?SelPg&t=9jD8Ej8w/BJlMPwStGqUK8dxpTSlacZKBpD8EsdvfCL2MP5tFhL4HvYGugr2EPyb_2OY2MsXbnr3s6/asupmiIy2ehXCbaVQPgtlZW9BRmDa4fV1VGZPd8S1lRNmkOgeY7x0GDBuCkjqsb2I3XTDPGrh7Tuitvm4GNO3oby2r5SaSCozqTsdCRi_u_M_TkYH6XUSBfTetLX8IvtZ6CT8

Thank you. Thought it might be the other one because I have dual a/c.