Darkness Beam via Amazon has DARKBEAM 365nm UV Flashlight LED Black Light (USB-C Rechargeable) on sale for $13.99 - $7 (apply promo code HYOIM6RA at checkout) = $6.99. Shipping is free with Prime or on $35+ orders.

• Note: Promo codes are typically for one-time use and don't always apply seamlessly. If you run into this issue, refresh the page, re-enter the code, or revisit the cart page.

Thanks to Deal Editor iconian for finding this deal.