OS Details

Apple iPad Air 10.5 (2019) has been launched in March 2019.
Apple iPad Air 10.5 (2019) have iPadOS 13.1.2

Screen Dimensions

Apple iPad Air 10.5 (2019) screen size is 10.5 inch with ~ 78.3% body ratio of actual device size. Physical dimensions for Apple iPad Air 10.5 (2019) device is 9.87 x 6.85 x 0.24 INCH or ( 250.6 x 174.1 x 6.1 MM).

Displaying of Units are in this order "Height x Width x Thickness"

Screen Pixel Density and CSS Pixel Ratio

"Pixel" is smallest unit/element of any display.

The total number of pixels that fit into an inch is referred to as "Screen Density" or "Pixel Density" and it measured as "Pixels Per Inch".
Pixel Desnsity have limits to display Pixels Per Inch depends on different screen sizes. When number of pixels per inch increases than it's screen-size limit, the Display resolution will increase but actual device width/height in pixels remain same. Actual device pixels are known as Device Independent Pixels or CSS Pixel Ratio.

Apple iPad Air 10.5 (2019) resolution is 1668 x 2224 ^PX with ~ 264 pixel desnsity.
Apple iPad Air 10.5 (2019) viewport size is 834 x 1112 ^PX with ~ 132 actual pixel density, which means it have 2 xhdpi display pixel density.

Screen Resolution and Viewport

The sum of pixels which are displaying on a device is called as "Screen Resolution". and sum of actual pixels of any device is reffered to as "Viewport".

Apple iPad Air 10.5 (2019) have 10.5" physical screen size and its resolution is about 1668 x 2224 Pixels with approximately 264 PPI pixel density. Apple iPad Air 10.5 (2019) has viewport size 834 x 1112 Pixels and its pixel ratio is about 2.

For better understanding screen actual sizes, viewport sizes, display resolution and about their density click here.

CSS Media Queries

Apple iPad Air 10.5 (2019) Only Media Query which covers portrait to landscape width.

@media only screen and (min-width: 834px) and (max-width: 1112px)  { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Media Queries (In terms of Tablets only)

@media only screen and (min-width: 768px) and (max-width: 1024px)  { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Min-Width Media Queries

@media only screen and (min-width: 834px) { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Min-Height Media Queries

@media only screen and (min-height: 1112px) { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Landscape Media Queries

@media only screen and (min-width: 1112px) and (orientation: landscape) { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Portrait Media Queries

@media only screen and (min-width: 834px) and (orientation: portrait) { /* Your Styles... */ }

Apple iPad Air 10.5 (2019) Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 264dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina is actually based upon device pixel ratio. Devices mostly have 2x or 3x display so you can use general retina media queries to display high resolution content on all kind of devices. Retina 2x and Retina 3x media queries given below:

Retina 2x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 192dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina 3x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 3),
  only screen and (   min--moz-device-pixel-ratio: 3),
  only screen and (     -o-min-device-pixel-ratio: 3/1),
  only screen and (        min-device-pixel-ratio: 3),
  only screen and (                min-resolution: 384dpi),
  only screen and (                min-resolution: 3dppx) { 
    /* Retina styles here */
}
                                

Apple iPad Air 10.5 (2019) Specifications

• Launch Date March 2019
• iPadOS 13.1.2
• Physical Screen Size 10.5 INCH
• Resolution 1668 x 2224 PX
• Viewport Size 834 x 1112 PX
• Pixel Density 264 PPI
• Device-Independent Pixels 132 PPI
• Pixel Ratio 2 xhdpi
• Width 1668 PX
• Height 2224 PX
• Device Width 834 PX
• Device Height 1112 PX
• Dimensions 250.6 x 174.1 x 6.1 mm (9.87 x 6.85 x 0.24 in)
• Weight 456 g - 1.01 oz