Looks to be off of an '07 H3x. Could be painted to match your truck easier than chrome.
http://www.ebay.com/itm/Hummer-H3-H...ies&hash=item35bf0e121e&vxp=mtr#ht_500wt_1414
http://www.ebay.com/itm/Hummer-H3-H...ies&hash=item35bf0e121e&vxp=mtr#ht_500wt_1414