This is a basic lens cleaning pen that includes a retracting brush and no-fluid carbon cleaning end that resides under a cover. Most products like this come with a clip for placing the lens pen in your shirt pocket. The advantage of a brush like this is it may be used in the field without any fluid so quick clean ups when someone accidentally fingerprints your eyepieces. Always make sure the brush is clean when using it.
For more information check out our eyepiece cleaning video.