Selkirk 6" rigid chimney pipe liner is a tried and true option and has a slightly smaller overall diameter then flex liners which can help in some installations. Available in 304 and 316 alloy choice.

Saf-T Liner 304-Alloy Rigid Chimney Liner - 6" x 12"L $42.41	Saf-T-Liner Rigd 316-Alloy - 6" x 12" $56.67	Saf-T Liner 304-Alloy Rigid Chimney Liner - 6" x 24"L $75.32	Saf-T Liner 316-Alloy Rigid Chimney Liner - 6" x 24"L $110.78
Saf-T Liner 304-Alloy Rigid Chimney Liner - 6" x 36"L $100.40	304-Alloy Rigid Liner - 6" x 15 degree elbow (Non-Adjustable) $58.82	Saf-T Liner 304-Alloy - 6" x 90 degree elbow (Adjustable) $112.61	Saf-T Liner 304-Alloy - 6" x 90 degree elbow (Non-Adjustable) $73.56
Saf-T Liner 304-Alloy Rigid Chimney Liner -6" Tee w/ Fixed take-off (snout) $137.90	Saf-T Liner 304-Alloy Rigid Chimney Liner - 6" Tee cover $37.32	Saf-T Liner 6-in Storm Collar $41.73	Saf-T Liner 304-Alloy - 6" x 45 degree elbow (Non-Adjustable) $58.43