This HOBO Pendant® data logger is a miniature, waterproof two-channel temperature and relative light level data logger.

• 8K model stores 6500 readings
• 64K model stores of 52000 readings
• Low-cost temperature with alarm indication
• Waterproof housing for wet or underwater use up to 30 m
• Data readout in less than 30 seconds via fast optic USB interface

This comes at a great value and is suitable for indoor, outdoor, and underwater applications.