I bought this as I have recently started making FIMO jewellery with my 9 year old daughter. After going int a local hobby superstore to get all the bits to get started (and being well and truly ripped off in the process!!!) I turned as usual to Amazon, found this kit. Excellent selection of open jump rings ( the type you use thin nosed pliers to twist apart then put your link or clasp or whatever finding you want in then twist and squeeze gently shut) sizes of rings are 3,4,5,6,7, and 8 mm, they come in the pictured clear plastic box which I have found to be sturdy, shuts well, I don't think there is any danger of the lids popping open and sending rings everywhere. I could only get 3 out of the sizes here in the superstore so definately a good selection of sizes even though I don't necessarily need a lot of some of them. The rings themselves, silver plated seem to be good quality, haven't broken or anything when twisting open and closed and seem very sturdy and secure. As the title says its a bumper box of essentials for jewellry making, definately recommend this especially as a starter kit or kids projects.