Keck Clips are used for holding the connecting joints of bongs together. One is usually used to secure the downtube or diffuser in the female joint of the bong, another Keck Clip can be used to secure an additional piece such as a Carbon Filter Adaptor.
If your bong has a carb-hole which you prefer to use instead of the separate slide bowl, then you can use another Keck Clip to secure the bowl more permanently.
Colours may vary.