Basic Info |
| Wear Type | Wristband | Wristband | |
| Price | | | |
| Ratings | | | |
Activity & Fitness |
| Activity | Yes | Yes | Both track daily activity |
| Calories | Yes | Yes | Both track calories burned |
| Sleep | Yes | Yes | Both track sleep pattern |
| Heart Rate / Pulse | Yes | Yes | Both have heart rate tracking |
| Distance | Yes | Yes | Both track your stride length |
| Steps | Yes | Yes | Both track how many steps you take |
| Stairs / Floors | No | No | Both don't have elevation feature |
| Exercise Tagging | No | No | Both don't have exercise tagging |
| Smart Coach | No | No | Both don't have coaching feature |
| Goal Setting | Yes | No | Set and keep your own daily or weekly goals with Mobvoi TicWatch E (Express) |
| Inactivity Alert | No | Yes | Polaroid B521 helps you stay active with inactivity alert |
Additional Features |
| GPS | Yes | No | Mobvoi TicWatch E (Express) has GPS support |
| Compass | Yes | No | Mobvoi TicWatch E (Express) has a compass |
| Watch / Clock | Yes | Yes | Both have watch |
| Alarm Clock | Yes | Yes | Both have alarm clock |
| Reminders | Yes | Yes | Both have reminder app |
| Stopwatch | Yes | Yes | Both have stopwatch |
| Music Playback | Yes | No | Only Mobvoi TicWatch E (Express) offers phone-free music |
| Weather | Yes | No | *Weather forecast |
| Reports | Activity, Sleep | Activity, Sleep | |
Smartphone Remote Features |
| Notifications | Yes | Yes | Both show smartphone notifications |
| Caller ID | Yes | Yes | Both show caller ID notification |
| Music Control | Yes | Yes | Both allow control smartphone music player |
| Call Control | No | No | Both don't have call control |
| Camera Control | No | Yes | Polaroid B521 has a smartphone's remote control function |
| Find Phone | No | No | Both don't have a find phone feature |
Battery |
| Duration | 2 days | n/a | |
| Battery Type | Rechargeable Battery | Rechargeable Battery | |
Physical Specs |
| Weather Resistance | Yes | Yes | |
| Waterproof | No | No | |
| IP Rating | IP67 | n/a | |
| Weight | 42 grams | n/a | |
User Interface |
| Display | OLED Screen | OLED Screen | |
| Display Size | 1.4 inches | 0,91 inches | |
| Screen Resolution |
400 x 400 pixels
|
128*32 pixels
| |
| Color Display | Yes | No | |
| Touch Screen | Yes | No | |
| Sapphire glass | Yes | No | *Scratch resistant sapphire crystal glass |
Compatibility |
| Android | Yes | Yes | Both compatible with Android devices |
| iOS | Yes | Yes | Both compatible iOS devices |
| OS X/Mac | No | No | Both don't compatible MAC OS X devices |
| Windows Phone | No | No | Both don't compatible with Windows Phone devices |
| Windows | No | No | Both don't have a find phone feature |
| Web Portal | No | No | Both don't have online web portal option |
| Social Features | No | No | Both don't have social features |
Connectivity |
| Bluetooth | Yes | Yes | Both have Bluetooth data transfer technology |
| Wi-Fi | Yes | No | Select Mobvoi TicWatch E (Express) if you need a built-in Wi-Fi connectivity |
| NFC | No | No | Both don't have NFC connectivity |
| ANT+ | No | No | Both don't provide ANT+ wireless technology |
| Buy on Amazon | | |
