The Impact 4 Socket Fluorescent Adapter can be used with at least 2 85 watt CFL lamps.

Yes! These lights would be a good choice for shooting smaller items. If you are looking to shoot larger items we would recommend a more powerful kit such as this 4-socket 3-light kit: https://www.bhphotovideo.com/c/product/945063-REG/impact_soft_n_natural_4_sockets.html

Yes you can use the Impact four socket adapter https://bhpho.to/2UTA7GA.

Yes. I purchased the kit for my daughter a couple years back. She has used them for both still photography and video recording using her Canon T3i.

It doesn't take speed rings, it has slots built into the housing.

It comes with 2 of everything you need: light heads, softboxes, stands, and CFL bulbs.

The sole concern here is heat output. Both LED and CFLs have built-in circuitry (such as the ballast for the CFL), so that's not a concern. Your 250W LED should not have failed to turn on for any circuitry reason. Bad bulb maybe? The brightest LEDs are still pretty novel tech, and so their performance can be hit or miss (even when paying a hefty price, and buying top brands).In terms of heat output, LEDs are very comparable to CFLs, at equal brightness ( equivalent wattage ). LEDs tend to give off only slightly less heat than an equal-brightness CFL. So the real question here is about increasing the actual wattage (NOT the equivalent wattage ) of your bulb, and not about changing from CFL to LED. So, let's discuss that ...In all product design, including softboxes, there is built-in safety margin, or over-design. The extent of this varies a lot, though. It's reasonable to expect better-made (more expensive) gear to have more overcapacity for everything, including heat dissipation. But how far you can cut into that safety margin is always a question.Keep in mind that LEDs and CFLs, while about 7 times lower heat output than incandescent, still put out some heat, and this can build up in long continuous use, especially in poorly vented spaces like most softboxes.As a starting point, I would not increase the actual wattage (from the original bulb) by more than 50 to 100%. So increasing from an 85W-equivalent CFL to a 150W-equivalent LED is within that it might be safe range.But I would ALSO watch for signs of overheating during use the first few times. Your earliest warning sign is a noticeably hot exterior, or the faintest signs of discoloration of the internal parts nearest the light after use. These indicate you're pushing it too far. If you get past that, to any burnt odor during use, or any deformation of the resin ( plastic ) mounting base, then you're WAY past the safe zone, and you're asking for a fire.TIP: If you can tolerate the direct light character, then taking off the front diffuser from the softbox will increase the heat dissipation, giving you more room to boost the wattage of the bulb. Similarly, up-facing orientations for the softbox can tolerate pushing the bulb wattage more, since hot air rises. (Down-facing orientations tend more to trap pockets of hot air inside the reflector.) In dire need, you could direct an area-fan to blow across the softbox (e.g., from behind), ... but only for still photography, since for video any fan would badly raise the noise floor.

I don't believe you can use this on a 220 circuit. It is only rated for 110