Replacement lamps for HID fixtures: single-ended and double-ended high pressure sodium for flowering, metal halide for veg, and 315W ceramic metal halide for full-cycle growing. Match the wattage and the base (E39 mogul, double-ended, or PGZX for CMH) to your ballast before you buy — a lamp on the wrong ballast will not strike, or will not last.
Ballasts, reflectors and socket adapters are in HPS & MH fixtures, ballasts & reflectors.