"Utilising COB (chip-on-board) technology the Slimline R50 is a great choice for visibility to other road users.Key Features
• Max Output 50Lm
• Runtime 2-45hrs
• COB LED
• Low battery indicator
• Waterproof IPX4
• Silicone straps and micro-USB cable included
• USB rechargeable 3.7v 500mAh Li-Pol battery
• Size (approx): 70mm x 25mm x 25mmModes & RuntimeHigh Constant: 2hrsMedium Constant: 4hrsLow Constant: 8hrsEco Constant: 15hrSlow Flash Low Beam: 45hrsSlow Flash Med Beam: 10hrSlow Flash High Beam: 6hrQuick Flash Med Beam: 23hr

Reviews
Given the affordable price tag, it's a mighty little unit - road.cc October 2018"