【400Ws Powerful Monolight】 NEEWER S101-400W is a professional studio monolight flash with 400Ws maximum power, 5600K consistent color temperature, GN65 high guide number (1m, ISO 100) for flexible flash distance and aperture settings—ideal for product, portrait, still life, food, commercial, and wedding photography 【Superior 150W Modeling Lamp】 Compact yet capable, the 150W modeling lamp has 9 brightness levels (L1–L9) and 7.0–10 (1/8–1/1) flash power adjustment to match ambient light conditions. 1/2000–1/800s flash duration and 0.4-2.8s recycling time help you capture every precious moment. The flash tube with a stable power output resists high heat, high voltage, deformation, and breakage. Memory function saves settings for the next time 【S1/S2 Optical Slave Modes】 It can work as a slave unit for diverse light effects, triggered by a manual master unit in S1 mode and a TTL master unit in S2 mode. It also works with the NEEWER RT-16 trigger receiver set (sold separately) for quick flash sync up to 1/200s within 100ft/30m 【Efficient Heat Dissipation】 The flash adopts optimized cooling fans and an enlarged air inlet for efficient heat dissipation. No overheating will occur even after 260 consecutive full power flashes for safe use and an extended lifespan 【Universal Bowens Mount】 To enrich light effects, the standard Bowens mount and umbrella socket can work with softboxes, photography umbrellas, reflectors, beauty dishes, snoots, and other light shapers. The metal stand mount adapter supports 180° tilt for free angle adjustment