Various sized "thumbnail images of " are listed below that can be saved to your computer, iphone, ipad or android device.
1) Right click on the thumbnail you need
2) Click on "Save Image As" to save the thumbnail.
Max resolution [1080p or 720p] usually 1280x720
Standard definition thumbnail [640p] 640x480
High Quality thumbnail [480p] 480x360
Medium Quality thumbnail 320x180
Mini size alternatives 120x90
Maximum size and standard definition thumbnails may not always be available. If you see grayed out image, it means image unavailable. Then go for high quality thumbnail
as for the highest quality option.