Suspension bush

[AquaHydroChem]

Hi

Can anyone tell me the difference between a ‘cross member bush’ and a ‘trailing arm bush’ for a Vauxhall vectra
Had a look on eBay and they bough look the same but got a printed quote a while ago can’t remember much about it them but they are two separate items
One says trailing arm bush – vectra 12.63 and the other says suspension bush – vectra 8.55 as I showed them the MOT fail certificate at the time which had written on it; cross member bush and trailing arm bush

Thanks

James