For Pentax K mount, you’ll find both Pentax-branded manual/auto-aperture extension tubes and third-party options. Pentax made tube sets and a useful helical extension tube; Kenko is a commonly cited reputable third-party maker for electronic/AF-capable tubes.

Key point: extension tubes contain no optics, so image quality differences between cheap and expensive tubes are generally not optical. The real differences are build quality and whether they preserve electronic communication.

For macro, autofocus is usually of limited value because depth of field is extremely thin and focus is often adjusted by moving the camera/subject. What matters more is aperture control. With many modern lenses, electronic contacts are helpful because they let you control aperture from the camera and may also retain lens data in EXIF.

If you use older lenses with aperture rings, cheap manual tubes can work very well. If you use newer lenses without aperture rings, electronic tubes are much more convenient.

So: buy dumb tubes for low-cost macro with manual-capable lenses; buy electronic tubes if you need camera-controlled aperture and lens communication. If you want the simplest, best long-term macro solution, a dedicated macro lens is still the more complete option.