Oh...okay...I see what he means now...he needs a place to get the probe into the box. Plenty of people use plastic tubs over here in the states for enclosures for snakes as well...and I actually do know what a RUB is because of our many UK members. I just hadn't heard the term faunarium before. And I wasn't following with the need for the hole and the probe...but I got it now! Yes...Wayne had shown us a pic of a little garter who had got his head caught in plastic slat openings, similar to the ones on those in the pic above, in the top of a common reptile keeper we have over here called a Kritter Keeper...broke his little neck. So you do have to be very careful with those...make sure the snake is big enough that it cannot get it's head into those slats....or any gaps like Mark is describing. Garters will make every effort to try to wedge their heads in any opening they can find...and they can flatten their heads and fit them into spaces a bit smaller then their head. Good job mentioning that, Mark.