Abstract: The string trimmer includes a connecting rod, a string trimmer head, and an operation part. The string trimmer head includes a trimmer line, a spool, a housing, and a streamlined protection structure. The spool is configured to wind the trimmer line and is capable of rotating about a first axis. The housing has an accommodating cavity for accommodating at least part of the spool and a threading hole for the trimmer line to extend to an outer side of the housing. The protection structure includes a head, a tail and a passage through which the trimmer line penetrates. The head is connected to the housing, the tail extends on the outer side of the housing, and the passage is configured to accommodate the trimmer line penetrating through the threading hole and expose the trimmer line out of the tail of the protection structure.

Abstract: A suspension type road traffic warning signs and a sign system are provided, which belong to the machinery manufacturing field. To solve the technical problem that warning signs must be set at 150 meters away when a car in operation breaks down, a solution is put forward that the warning signs (1, 2, 3, 4) and the sign system (5, 6, 7, 8) are assembled with balloons (1-2, 2-2, 3-2, 4-2), scrolls (25), heavy objects (14), miniature remote control cars (5-1), miniature helicopters (6-1), small rockets (9), skidding tools and car rods (17). The suspension type road traffic warning signs and the sign system are suitable for the condition that warning signs must be set when cars are broken down in driving.