Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: SainSonic&reg LOOPER SS-C60L LED Macro Flash Light + Rings Work with Flash Triggers for Canon Digital SLR Cameras Digital EOS Rebel SL1 (100D), T5i (700D), T4i (650D), T3 (1100D), T3i (600D), T1i (500D), T2i (550D), T1i XSI (450D), XS (1000D), XTI (400D), XT (350D), 1D C, 60D, 60Da, 50D, 40D, 30D, 20D, 10D, 5D, 1D X, 1D, 5D Mark 2, 5D Mark 3, 7D, 6D
Product description: The SainSonic LOOPER SS-C60L LED ring flash is the perfect macro lighting solution for your DSLR camera. It operates smoothly, giving you steady, bright, and uniform light to achieve your desired photographic effect. It also provides 6 modes: full brightness or left or right-side, either continuously or as a flash, to meet a variety of needs. Half-pressing shutter can easily activate AF-assist lamp. There are stops of brightness adjustment. Use the appropriate ring mount according to the size of the lens, place the ring mount on the lens, hold lock and place ring flash on the ring mount. This SainSonic ring flash works like it should and exactly as you would think it does. The controls are friendly and easy to figure out. Be you a beginner or crazy fans of photography, you can use this device to deliver the light where you need it, and it is definitely the best partner with you. Specifications Power Supply: 4 x AA Batteries (Not Included) Voltage: DC 3. 6V-6. 7V Effective Flash Range: 5cm-1. 5cm LED Quantity: 60 Color Temperature: 5500K300K Average Life Span: >50000 Hours Bulb Angle: 60 Degree Sync Speed: >1/200S Light Color: White Ring Flash Size: 10. 3 x 2. 2cm/ 4. 1" x 0. 9"(D T) Ring Flash Controller Size: 9. 5 x 7 x 3. 5cm/ 3. 7" x 2. 8" x 1. 4"(L W T) Cable Length: 60cm/ 23. 6" Material: Hard Plastic, Electric Parts Package Content 1 x Digital LED Video Light 1 x User Manual 8 x Rings (mounts for different lenses: 49mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm. )
Product feature: New LED technology, providing continuous, stable light., Brightness adjustment wheel., Flash mode light output is twice as high as continuous mode., New functions to meet higher shooting demands., Left and right flash for more dynamic effects.
Product brand: SainSonic
Target attributes: Guide Number
Answer: attribute: guide number
value: None
source: None