... 2.Size:different size 3.Used for glass bottle,pot,canister,tube, Pipe rubber stopper for test tube 1. Material: 100% ... Food grade silicone 2. Size: Different size3. Used for glass bottle, ceramic ... . StandardOrNonstandard:Style: Size and Color:Material: Nonstandardrubber stopper for test tubeas your requests,drawings or samplesRubber(NBR,SI, Viton, ...