Guide bar cover 18″ fits 4500 (45cc), 5200 (52cc) and 5800 (58cc) Chinese chainsaws and also Plantiflex, BBT, B&Q, Silverline, Sanli, Whitemoss, Skatco, Eckman, Timbertech, Tarus and MT-9999 chainsaws. The guide bar cover is the protective plastic scabbard that slots over the guide bar and chain when the saw is not in use, preventing accidental contact with the sharp chain cutters during transport and storage and protecting the bar tip from knocks and contamination. A missing or broken cover leaves the chain exposed, creating a handling hazard and risking damage to the guide bar nose and chain cutters. Fitting a correctly sized replacement keeps the saw safe to handle and the guide bar and chain in good condition between uses.