Simple and easy to operate with a single button, so even beginners can use it. On the other hand, it has plenty of functionality. Similar to other models, it has 4 different modes: Air, Nitrox, Gauge, and Free-Dive modes. It also includes a warning sound that notifies you of not only visual but also sounds, and a high visibility LED warning light. User battery can be replaced. Main Features: User can update the software by themselves, change to the latest functions and versions (need to purchase a separate download cable). Pre-dive function useful for your next diving plan. Water detection activation function allows you to automatically switch to dive mode. One button can check the previous dive history (maximum depth and submersion time). In historical mode, the maximum depth, total water temperature of 1. Supports up to 00% Optional deep stop function with countdown timer. -You can choose saltwater or fresh water. -Automatic altitude adjustment function will always obtain accurate profiles. -Easily use the diverlog software using Mac, PC, or mobile phone. -Requires a separate USB download cable. -You can also store and share photos and videos, as well as set up and record your dive computer (dive log must be purchased separately at ediverlog.com) *Batteries shipped from ediverlog.com). As this is a monitor battery, it is an estimate. It may break faster than before. Please acknowledge