Celestron 93653-A 1.25-Inch Visual Back Metal Adapter (Black) Allow for the attachment of 1.25" eyepieces or accessories The equipment slides into the Celestron Visual Back and is held securely in place by thumbscrews. This item accepts 1.25" accessories, including diagonals, eyepieces (for straight-through viewing), Barlow's, webcams, and any other accessory with a 1.25" insert barrel.