Red Measuring Sight, Gauge, Sight Hole Kit for 17 to. 78 Caliber Shotguns, Equipped with 7 interchangeable connectors (0.17-0.78)

It feels robust and good quality but doesn’t turn on??

Initially I was unable to install the battery compartment into the unit, it just got wedged. Having released it with pliers and trying again it went in. Problem was the contact on the end of the battery compartment doesn't line up with the contact in the unit. As it's basically a pin head locating in a recess, and it doesn't line up, it's never going to work. Returned.

I took a punt on this as had read a few reviews saying they had to send it back. When first setup I thought I'd made a mistake and would also be in that camp, but I had another look at the 'Chinglish' instructions and worked it out. It's not clear from the picture how the battery pack goes into the unit. The battery's go in the little plastic tube negative side first and the whole plastic tube slides into the unit with the closed end (with the small metal contact pin sticking out) first. Then the large spring goes onto the top of the plastic tube so that the larger diameter end sits on the plastic tube (not the batteries) and the small end locates into the laser section. The laser section then screws down into the body to make contact with the batteries. Once I got this setup correct the laser lit up and works well. There's no on/off, you just screw in the unit to turn on and then unscrew to turn off. My airguns are generally all 0.177 and it fits nicely down. Rotate the unit to get the little insert to 'lock' in place and stop it falling out the barrel. I set up red dot sights and scopes using this and it worked really well. Nice to have with the gun if changing distances so you can sight in without needing to make test shots first. Also good for checking fixed sights on things like replica pistols etc to see if you need to adjust your aim slightly. As usual, remember to remove it before you take a shot - been done before and will be done again. Overall a nice little boresight and just knocked a star off for the poor instructions to setup - I think a few will have sent back thinking it was broken but just needed to find the correct battery installation.

It's a good bit of kit

Poor design, battery housing is impossible to get in without force, batteries are difficult to put in the right way round once you actually do manage to do so the thing doesn’t turn on, sent back for a refund.

Inserts are quite fragile and easily broken. I have used female Velcro on the tool and have a perfect fit down the barrel. The laser is powerful enough and all my sights are now on target.

10 minutes and done exactly what I needed

When I first got the item as mentioned in the reviews the instructions was a little vague but soon worked it out I used the item to set up my air pistol and my pcp air rifle I got to say I was impressed at the accuracy would definitely recommend but would say if your not using the item for a while it’s best to remove the batteries I have left a picture to show how the batteries fit in the unit but altogether a spot on unit