identify this ?? and whats it for

hi people. recently my discovery started having problems and the bearing blew, the one with the arror pointing, and then after a while the belt chewed itself tobits, can anyone please tell me the part number for this and what it is for ? and if it is neccesery to run the engine ? thankyou,
sam.

Sambo... Is it you??? Hows your turbo?

yea tis me lol. and ant got the turbo yet, prob been posted today so hopefully will get it tomoro or monday or sumat. guna be geting all me oils and stuff for gearbox soon 2 lol

have sent u a pm.

Is it the aircon/compressor belt idler?

thats wat every1s saying and so is ebay lol. thankyou, just need to know as getting another at weekend. and the belt 2 thankyou