TheWolf Tooth B-RAD 4 Mounting Baseis created from lightweight, durable, rust-proof materials.Bases are the foundation for theB-RAD systemand the rest of theB-RAD systemmounts to them. Wolf Tooth B-RAD 4 Mounting Base Features Reposition bottle cages using existing bottle cage mounts on your bike. Customize storage to your specific needs with flexible B-RAD system B-RAD 2 -The 2-Slot Base can move bottle or other accessory to an optimal location even on a smaller or dual suspension frame B-RAD 3 -The 3 slot base with 4 threaded holes provides additional adjustment and mounting options vs the B-RAD 2. A typical application would be to mount a bottle cage in the forward threaded holes with a B-RAD accessory tucked behind it ... More info