The SEER SFL-300L is a single-fork autonomous forklift with a 400 mm body width designed for narrow aisles with a 600 mm minimum aisle width and 650 mm turning radius. It measures 914 by 400 by 1,576 mm and weighs 230 kg with a 300 kg rated load, 350 mm load center distance, and 150±5 mm standard lift height on a 480 by 300 mm fork. Four navigation methods of SLAM, QR code, reflector, and NFL achieve ±10 mm and ±1-degree positioning accuracy. A pallet recognition camera supports real-time cargo detection and stable pick-and-place even on tote dollies without fixed grooves. Ground clearance is 20 mm with a 3 percent slope, 2 mm step, and 5 mm gap passability. A 48 V 35 Ah ternary lithium battery provides 8-hour runtime with under 1.5-hour charging. Maximum speed is 0.8 m/s full load and 1.4 m/s no load. Multiple safety sensors including navigation lasers, obstacle avoidance lasers, 3D cameras, safety edge sensors, and photoelectric sensors provide 360-degree protection, with braking distance under 30 cm at 1 m/s. Modular design allows customization of height, color, and branding. Standard features include E-stop, sound and light indicator, 360-degree laser protection, bumper strip, fork height protection, Wi-Fi roaming, pallet recognition, and HMI display. 3D obstacle avoidance is optional. Targets industrial logistics and warehouse narrow-aisle material handling.