Those crimpers are all for Yellow, Blue & Red terminals. Three of them can do both heat shrink and standard double crimp insulated terminals and one pair only does heat shrink terminals. The two crappy ones on the left are just that JUNK and have not seen use except for non-crimping duties. I generally always use the two AMP tools on the far right as they are aircraft industry certified and inspected tools that make, by far, the best crimps, but of course cost a boat load of boat bucks too....