- Men’s white shirt - London collar, long buttoned sleeves - Easy-Regular fit - Buttons to fasten, IKKS button on left cuff URBAN LAB line 37.5° tech using natural volcanic sand particles, fused with polyester fibres, enabling the body to be kept at a perfect temperature of 37.5° and humidity level at 37.5%, for all-out comfort. Discover the entire URBAN LAB line « Protect the planet and your clothes when you wash them by using a GUPPYFRIEND® wash bag » 37.5°, is the human body’s perfect temperature. This white shirt, designed using natural volcanic sand particles, fused with polyester fibres, tends to keep it. Get into total comfort.