This polycarbonate cylindrical type fluorescent hand lamp with built in ballast has the following advantages: 1. This line light will not break easily if it is hit or dropped. 2. It is waterproof. 3. If the fluorescent lamp is broken inside, this line light is not liable to ignite. 4. Since pieces of broken glass will not scatter, it will not cause damage to any apparatus. 5. This line light is cold-proof so that it can be used in any cold place.