Beam splitters take on many forms, cubes, plates, hexagons, pentagons, polarizing, non -polarizing (usually somewhere in between), narrowband, broadband, dielectric, air-spaced, metal, cemented, optically contacted (epoxy free bonding)... It is our job to help you sort out specifications that will meet your requirements for performance and cost.
Some of the key parameters to think about are; the wavelength range, polarization and physical size requirements. Also, if the beam splitter will be used inside an interferometer, you may need to consider path length and phase matching requirements. It is always good if you can explain how you will be using your beam splitter, it can really help us to define out your requirements.