Main Features of Nikon Speedlight SB-400 –

Compatible with i-TTL and D40’s M mode
Flash head can be tilted in 4 steps; horizontal, 60, 75 and 90 degrees
Flash shooting distance range: 0.6m – 20m (depends on the ISO setting)
Guide number: 30 [ISO 200, m, 20°C]
Angle of coverage: 18mm (with Nikon-DX format cameras), 27mm (with Nikon F6)
Power source: two AA-size 1.5V batteries (also compatible with lower voltage batteries)
Flash modes available: Slow Sync, Red-eye Reduction, Red-eye Reduction with Slow Sync, Rear-curtain Sync, FV Lock, exposure compensation, M (manual, only with D40 camera)

Supplied Accessories with Nikon Speedlight SB400 –

• Nikon Speedlight SB400
• Soft case SS-400

Technical Specifications for Nikon Speedlight SB-400 –

Electronic construction – Automatic Insulated Gate Bipolar
Guide number (20°C/68°F) – 30/98.4 (ISO 200, m/ft), 21/69 (ISO 100, m/ft)
Flash mode – i-TTL, M (manual, only with the D40)
Recycling time – Approx. 3.9 sec. with alkaline-manganese batteries
Number of flashes – Approx. 140 times with alkaline-manganese batteries
Compatible cameras – All cameras compatible with Nikon Creative Lighting 
Bounce capability – Flash head tilts up to 90° with click-stops at 0°, 60°, 75°, 90°
ON/OFF switch – The ON/OFF switch turns the SB-400 on and off
Flash duration – Approx. 1/1300 sec. at full output
Dimensions (W x H x D) – Approx. 66 x 56.5 x 80mm (2.6 x 2.2 x 3.1 in.)
Weight (without batteries) – Approx. 127g (4.5 oz.)