Pictures, a 50 mm with hanging hole. An 80 mm with hanging hole. The 120 mm sitting on the flat, showing a 50 mm being held with widest part in line with the plane of the flat. A 2 inch (25 mm) t pin being held on the flat. All sitting on 7-hole/inch plastic canvas. A standard sharpie marker also for scale.Now that one can see the relative sizes of these spheres... the 120 mm is about 2 kg-KILOGRAMS. About 4 1/2 POUNDS. Of solid glass. Massive. HEAVY.The 50 mm is big. The hanging hole (in pictures has a t-pin stuck through it) will take a 12 gauge wire (sometimes) and a 14 gauge wire period. I suggest using nothing finer than a 20 gauge wire. IF you use fishing line (monofilament) use at least 20 lb test and new line, double crimp. Be careful that breezes can’t make it swing, it could possibly break your window. It needs a secure hang. Small cup hook is out, ant don’t use push pins, thumb tacks, upholstery tacks or nails, and no brads.80 mm is about the maximum one dares to hang. Same wire issues as a 50 mm but don’t go finer than 18 gauge. No fishing line. This size needs serious fastening, swag hook, regular hardware hook or hardware eye set into real wood. Also one does not want to get this swinging.Any larger than an 80 mm, the volume goes up swiftly. Glass weighs a lot. The 120 mm comes in at two kilograms. 4 1/2 pounds. It’s possible to suspend but. Glass is breakable. It can have internal stresses. It’s not that “tough” (okay maybe borosilicate, but that doesn’t make good rainbows). Trying to put a hanging hole would not be easy and look kind of ugly, and with that much weight, be more prone to chipping out or breaking. Once one goes past an 80 mm, don’t try to suspend a glass sphere.(50 mm is about 2 inches, 80 mm is about 3 1/8 inches, 120 mm is about 4 3/4 inches)Now, refraction and rainbows. K9 is glass, not plastic/acrylic or resin. It’s NOT lead crystal. Lead crystal has a percentage of lead metal in it that changes the refractive index of the glass and gives sharp bright rainbows. It can also leach lead into stuff that stays in contact with it for long periods of time. (Decanters full of alcohol). For drinking wine or whiskey out of, it’s fine. For hanging on chandeliers and lights, it’s fine. For pretty bits to hang in your window, it’s fine. Don’t let the little ones suck on them. One brand name is Swarovski. Jewelry it’s also fine.These are made of K9 glass. It is Lead-FREE. It is still a good clear optical glass, and will make nice rainbows in the sun. Not quite the same as lead crystal, but there is no lead, and K9 glass is a lot more affordable.Can things be caught on fire from one of these catching the sun? Yes it is possible, but odds are very low. Not impossible, just low. (The old glass doorknobs, bottles of vodka, and rainbow making crystals have all done it) most of those everything had to be just perfect. This worry is very very low.This particular item, 120 mm K9 glass faceted sphere with an adequate flat of about 45-50 mm. You really don’t notice that flat when that sphere is sitting on it. It’s big enough the big heavy chunk of glass will stay wher you set it. It’s gorgeous, it’s stunning, it makes a great statement piece. If you are into that sort of meditation practices, it is a great alternative to a “crystal ball” ( put the flat up ina legged ring holder for a “seer window”. Do not put a candle near or under it though. One of those led color changing bases or holders are okay. Just make sur it is large enough and able to hold the weight.Gift potential????? Oh yeah!!!!! Awesome.Do make sure to examine it as soon as you receive it, for shipping damage. Packing may not be adequate for any size, and the 120 is big enough and heavy enough to escape packing material and get a point chip.Yes this is long. Hope it covers questions. My personal? (Ahem...) Wow. Just wow. After cranking my jaw up. Pictures can’t do this justice. Stunning. Wherever you place it, it’s going to be awesome. Great gift idea too. Add sun, yeah,