These appear to be very well made 3/16" quick connectors for .020" (0.5mm) thick tubing. The contact interface has sufficient coverage, the contacts are well formed into double round springy curls, and the flat area is properly divided and embossed into contact holding areas, the material has good resilience, the contacts achieve good normal force (surface pressure) for low contact resistance , no scraping of plating Crimp ferrule is the correct size for 16-14 AWG stranded wire, is round, has internal retaining grooves, has a tab to prevent wire insertion, is good gauge and has a well formed ferrule crimp In short, they have the right design, are made of the right materials and are shaped correctly. Mislead people with rave reviews about a product that is unfit for purpose. They are not suitable for every application and can affect their performance if used incorrectly. The spade lug accepts 16 AWG or 14 AWG stranded wire only. They will loosen (over time, if not immediately) and fall off the fixed wire. Crimping the ferrule for use with smaller wires will result in cracks in the coating and poor wire retention, and may also result in thinning/cutting of insulation etc. It is also necessary to use a reasonably well insulated crimping tool and the correct crimping technique for the specific tool. They are designed for use with 3/16" (.187") wide tabs, not very similar but slightly wider than .205". It is very important to note that these pins are specifically designed for .020" thick spade lugs, not thicker ones. Projection 0.032 inch. If a socket contact for .020" leads is used with .032" leads, insertion will be very difficult, the contacts may be bent or broken when attempting, the tinned contact surface may be chipped or worn after a few insertion/removal cycles. Buy when in doubt, as many types as needed to ensure you have the right one as repairing a broken terminal lug on an appliance can be very expensive i Insulated connector rated at 105°C (e.g. Morris 11918) in hot locations such as air conditioners , stoves, electric motors, kitchen appliances that get hot, anywhere the original connector was a harder and more transparent nylon, or where the wire is a high temperature wire or a thermoplastic insulated wire rated at 90°C or more, etc.