Selecting a smart padlock requires balancing security, durability, and connectivity. Buyers should prioritize zinc alloy or stainless steel bodies for physical strength and hardened steel shackles to prevent cutting. For outdoor use, ensure an IP65 or higher waterproof rating to protect internal electronics from rain and dust. Additionally, verify the biometric sensor quality (0.5s recognition speed is industry standard) and the battery life cycle, ideally supporting over 2,500 unlocks per charge.