Maddie, I have neither of those. It is a comparator with two tubes and came with the Taylor K-2006C Test Kit. Here is a picture:I just want to confirm that your comparitor block is the one with the large round tube section for pH, not the smaller square tube? Both are from Taylor and they use different reagents (both phenol red though) so this might explain the confusion??
View attachment 93207 Or this smaller one from the Basic Taylor K-1000 kit==>
HDX/PoolMaster Kits to Test PH - Not a good idea