This is a replacement spherical glass globe, size S, for the small Campingaz Bivouac gas lantern. The glass protects the mantle and flame from wind and spreads the light, and it is the part that breaks most easily if the lantern is knocked or dropped. Keeping a spare in your camping kit means a cracked globe does not end your lantern's life. Fit it according to the lantern's instructions and never use a gas lantern with a cracked or missing globe. Check that your lantern is the Bivouac or another Campingaz model taking the size S spherical globe before ordering.