Zoom icon Click to expand Tap to zoom Chevron down icon Chevron down icon N91 Medical Alert Nylon Watch Strap by PERRIN Sale $21.95 | / SKU ST-N91-1-20L-MED 20 mm long black - $21.95 20 mm long black Size and Colour Chevron down icon 1 2 3 4 5 6 7 8 9 10+ Quantity Chevron down icon Quantity Add to cart Spinner icon Notify me when back in stock Email address Email me when available N91 Medical Alert Nylon Watch Strap is available in black in 20 mm long. This is an athletic and simple looking watch strap complete with medical alert. The steel plate size measures 48 x 24 mm and is perfect for custom engraving.