.Prop 65 warning Open top aluminum seal with ptfe/red rubber septa size: 11mm designed use with 12 x 32mm crimp top vials open-top seal provides for filling or retrieving contents with a syringe and as closures for many autosampler and instrumentation applications. Wheaton® 11mm Crimp Seal, Aluminum, PTFE/Red Rubber, Case of 1000 Wheaton 11mm seal, aluminum, ptfe/red rubber. Warning: this product can expose you to chemicals including tetrafluoroethylene, which are known to the state of california to cause cancer.