Adjustable Grade Rod Level, Bubble Level for Aluminum Builders

【High Sensitivity Adjustable Circular Bubble Vial】Features an adjustable vial with 40 minute sensitivity. The high-precision circular spirit bubble delivers accurate vertical plumb readings, helping surveyors precisely calibrate survey poles and reduce measurement errors for total station, GNSS and field land survey projects. 【Sturdy Die-Cast Aluminium Body Construction】Made of integral die-cast aluminium with anti-rust orange powder coating, the housing is shockproof, wear-resistant and deformation-proof. It can withstand harsh outdoor construction site environments for long-term repeated use. 【Convenient Keyhole Slot Mounting Design】Built-in keyhole-shaped hanging slot on the side, allows quick fixing and binding onto survey poles with straps. The 90-degree offset bent structure keeps the bubble visible without blocking pole operation. 【Compact Portable Size for Field Survey Work】Ergonomic L-shaped slim profile takes up little storage space, lightweight to carry in survey tool bags. Perfect for outdoor topographic survey, engineering layout, construction stake-out tasks. 【Wide Compatibility for Various Survey Poles】Suitable for round and rectangular survey poles with a diameter of 1 - 1.25 inches. The keyhole mounting slot allows quick and firm installation using binding straps, easy to fix onto your centering staff securely.