This is a battery holder for Pentax 645. ☆Some people occasionally mistake this for the 645N and purchase it, so please check your camera again. (For 645N.NⅡ, it is also listed at the same time) (Images 1 and 2 show the item installed. The actual product is shown in images 3, 4, and 5.) YouTube "Hitori Photo" is distributing a video titled "There was a substitute battery holder for PENTAX 645!". This was made as a replacement for a battery holder that became unusable due to leakage, or for those who find it difficult to carry many spare AA batteries. This is not a genuine product, so the holder cannot be locked. It is fixed by the friction of malt and the force of the spring, so it may come off if strong force is applied. (We have sold several, but there have been no problems with them coming off.) One battery (006p) is included.