Temperature-cycling best seals for downhole tools survive 50+ cycles from 40°F to 650°F in thermal wells. Special low-compression-set FFKM maintains sealing force. Ideal for cyclic steam and SAGD. Heavy oil producers choose the best seals for downhole tools that endure thermal shock. https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/