511 front tower?

[sime46]

Hi all. I see a few are using what appears to be a thicker than kit front shock tower. I was wondering where these were from? I've lent my spare tower to a mate who I not seen for a few weeks and want to run at the regional on sunday so a spare or thicker one would save any issues. My friend prob still has mine on his car so if I pinch it back for spares he can't run. Something uk based prob means it'd be here in time I'd hope. Fingers crossed. Thanks.