1.625" Long X 1.10" Diameter. Fits 1 1/8" ID mortar tubes & star guns. This two piece (with cap) plastic shell is designed for use as an insert in larger aerial shells for special effects or shot from a star gun of 11/8" ID. Its design allows for a delay well for pressing a spolette with a flash hole to ignite the main charge of flash for thunder or small stars or mine mix for spectacular visual effects. The spolette well can be filled with color star compositions for color delay as well.