Twin Slot Shelving - White

Does anyone know if twin slot shelving is a standard ? I have some brackets from B&Q but they didn't have the tracks in stock Screwfix do but

HULK Twin Slot Shelving System

twin33 slot Our Twinslot shelving offers a modular and affordable shelving system which is simple & easy to install Our wall-mounted Twinny shelving is versatile and

twin dragon online slot game Product Detail The Twinslot Shelving system is designed as a simple 'upright & bracket' arrangement, for supporting various types of timber shelves