Rain Bird® A11466 VBLOCKH Hex Head Locking System for Valve Box. When a project requires quality valve boxes, look no further than Rain Bird’s VB Specification Series. Sure, the VB Series may be priced slightly more than a basic valve box, but they eliminate unnecessary expenses associated with a lesser quality product: lost or damaged lids, crushed valve boxes, or pest infestation, making the extra investment in the VB Series worth every penny!