VALYRIA 500pcs Siver Tone Stainless Steel Open Jump Rings Connectors 0.8mm Fit Jewelry DIY (4x0.8mm) Dia:4mm(21-Gauge);Hole size:2.4mm Thickness:0.8mm Dia:5mm;Hole size:3.4mm Thickness:0.8mm Features: durable and fadeless Professional jewelry makers' must have Jump rings are used as a connector where a single ring is desired.