This off-axis guider is no longer commercially available as Lumicon has gone out of business. It will be hard to match. It's designed for 10 in. or larger SCTs. The guider has a 3.25 in. aperture and the reducing lens is 80mm in diameter. This fully illuminates a 35mm frame with no vignetting. The reducer lens can be positioned to give you either f/6.5 or f/5.5 operation. The eyepiece/autoguider extention tube has been modified; it was shortened and has additional extension tubes added (this helps achieve parafocus with a variety of focal ratios). This guider has a Pentax K mount adapter but all you would need to do is replace it with a t-ring for your particular camera. Original documentation is included.