Writes Through: The Permanent Ink Writes Through Water, Grease, And Mud Without Clumping Or Smearing.

Pressurized Cartridge: All-Weather Cartridge Is Pressurized, Writes In Temperatures From -30F To 250F, Under Water (Up To 35 Ft.), And Any Angle.

Proprietary Ink: The Ink And Delivery System Used Exclusively In Rite In The Rain Refills Will Write Without Skipping In Extremely Wet Conditions Far Better Than Other Comparable All-Weather Pens.

Ink Delivery: Tiny Pockets In The Pen'S Tip Will Deliver Ink In The Worst Conditions Without Allowing Water Or Air Back Into The Cartridge.