I own both an original Pentax battery grip and a Meike knock-off grip for my K-5. The short version of the story is the original one developed a fault and I had to send it to CRIS, while it was gone I used the $39 knock-off because I was so used to having a grip that I was fumbling with the K-5 without one.
There appear to be two main knock-off versions of the grip available. Mine is the one that does not have the circle of screws visible on the attachment side of the grip and is marketed under the name MeiKe. Based on the reviews here the main difference appears to be that the other version's battery trays will work in the original OEM D-BG4, those that come with the MeiKe version will not.
For an analysis of the differences between the two main knock-off grips see this post here on PF:
https://www.pentaxforums.com/forums/p...tml#post850074
My comparison of the Meike and Pentax Grips:
- The trays are NOT interchangeable between the two grips.
- The covers for the pins and the base of the K-5 do fit in either grip for storage.
- Both have an SD Card slot on the D-Li90 battery tray.
- Both have the same buttons and wheel layout.
- Wheels are a bit more abrupt in their movement on the MeiKe version.
- On-Off switch moves backwards on the MeiKe from the OEM version.
- Fit & Finish on the OEM is better overall but the MeiKe version is not bad.
- Both fit snugly to the body, but the OEM unit is better contoured and fits the hand better.
- OEM has steel placement pins to guide fit to the body, the MeiKe version has plastic pins
- Both have offset placement of the tripod point on the bottom.
- Packaging was fine with each, box, bubble wrap, warranty card, and instructions.
Overall, the Meike is a great buy for $39 if you do not need WR for the grip. I'm annoyed that the D-BG4 from Pentax failed after only 10 months but CRIS fixed it in pretty short order and it's been working fine ever since. I do still own the Meike grip though, because you never know and it was only $39.