Their only difference is with magnets on the buttom and without magnets on the buttom. the red color has magnets on the buttom. It can display both degree and slope. have two versions---with magnets on the buttom and without magnets.
eBay
Electronic Protractor 2 IN1 200mm/300mm Digital Angle Ruler Inclinometer Angle Finder Digital Angle Gauge 0-360 Degree
Aliexpress UK
Angle and slope readout conversion. Four side built-in powerful magnets. Line Laser Accuracy:±5mm/2m. The display will be turn off if you don't operate the device within 30 seconds ,the dispaly will automatic turn off if you don't operate it within 3 minutes.
eBay
2-in-1 Digital Angle Ruler, Protractor, Inclinometer, Digital Angle Meter, Electronic Goniometer, Angle Finder, Measuring Tool
Aliexpress UK
Type: Digital Angle Finder (With Laser). 1 Magnetic Digital Angle Finder with Electronic-Laser. Battery: 3.7V Lithium Battery.
eBay
2-in-1 Digital Angle Meter Inclinometer Digital Angle Ruler Electronic Goniometer Protractor Angle finder Measuring Tool
Aliexpress UK
Protractor 1. Purpose: adjust the horizontal angle. Sound & Vision. Range: 0-90 degrees. Set includes hope you could understand. Precision: 0.1 degree. Color: black.
eBay
200mm /300 mm Digital Meter Angle Inclinometer Angle Digital Ruler Electron Goniometer Protractor Angle Finder
Aliexpress UK
Digital Protractor 1. Fall and impact resistance: Adopting a thickened end cap design, the level ruler has strong impact resistance. Size Length Width Height Weight.
eBay
Shahe 200mm Electronic Protractor Stainless Steel Digital Angle Ruler Inclinometer Angle Finder Digital Angle Gauge
Aliexpress UK
Angle and slope conversion. Processing: precise positioning of the working angle of the machine tool, rotation angle of the boom. Size: 60 30 55mm. Display resolution: 0.05°0.05°(<100°), 0.1°(100°~180°).
eBay
12Inches/300mm Digital Angle Finder Digital Protractor with Zeroing and Locking Function Stainless Steel Digital Angle Ruler
Aliexpress UK
Display Screen Auto Reversed. Small and Light Makes it Convenient to Carry. Weight : 80g/0.17lb. Material type : Plastic. Battery type : 2x1.5V "AAA" batteries (not included). Resolution : 0.05°. Accuracy : ±0.2 °.
eBay
Huepar Digital Angle Gauge AG2L 3-1N-1 Digital Angle Gauge Magnetic with Laser Level Inclinometer for Decorations Woodworking
Aliexpress UK
Type: Digital Angle Finder. 1 Magnetic Digital Angle Finder. TYPE-C CHARGING PORT AND CONSTRUCTION: Featuring a Type-C charging port for quick recharging, this gauge is made from materials for long-lasting performance, while being compact and lightweight for easy portability.
eBay
400mm / 250mm Digital Angle Finder Gauge 0-270Degree Protractor Ruler Miltre Angle Finder meter Spirit Level Back-Light
Aliexpress UK