C.E. Smith Aluminum Clamp-On Rod Holder - Horizontal - 1.90" OD [53730]Aluminum Clamp On Rod Holder Horizontal 1. 90" OD Smith's line of high polished aluminum clamp on rod holders offer a great alternative to stainless steel. These rod holders are constructed of marine grade aluminum that has been 100% anodized for functionality and style. These rod holders feature a super strong 3 8" thick blade, rugged welded 1 3" tall gimbal bar, and a 1 5 8" inside diameter with a flared opening to make it easy to insert a rod in