The TF-321 from Pixel is a hotshoe adapter for Canon cameras. It allows you to still pass the TTL signal to your speedlite flash, but at the same time benefit from the flash signal on the x-contact port. This way you can have your speedlite flash unit and external studio flash unit flash simultaneously. Depending on the situation, it is also possible to use only your studio flash unit and leave the speedlite flash unit behind. In short: the TF-321 is a total solution that allows you to control the right flash light anywhere, anytime. The special feature of the TF-321 is that, in addition to the center contact, the additional contact points of your Canon camera are also used. In this way, it is possible to employ E-TTL, so that light metering takes place through your camera lens. The prerequisite is of course that your Canon camera and speedlite flash support this. The TTL signal is not passed through the X-contact, but you can only pass it to the speedlite flash via the hotshoe on the top. The TF-321 feels very solid. You attach the hotshoe adapter securely to the hotshoe of your camera, thanks to the dial. The universal x-contact cable can be found in the optional accessories.