Diabetes insulin pen needles are an essential accessory to the Insulin Pen which is used for quick and efficient delivery of insulin into the human body. Pen needles fit most “Type A” insulin pen devices which covers most brands throughout the world, but please refer to each individual needle for specific fitment. Pen needles offered in our store come in different needle gauges (thickness) and needle lengths. Needle length is a pretty straightforward attribute, the bigger the number the longer the needle. Insulin needle lengths are 5/32in (4mm), 3/16in (5mm), 1/4in (6mm) also known as 15/64in (6mm), 5/16in (8mm), 1/2in (12.7mm), 5/8in (15.9mm), and the largest is 1in (25.4mm). Needle gauge is where things get a little trickier as the gauge number is the opposite to size (needle diameter). Bigger gauge means thinner needle diameter, while smaller gauge would be a thicker needle. A 31G (0.25mm) needle gauge would be much thinner than a 25G (0.5mm). Insulin needle gauges are 32G (0.23mm), 31G (0.25mm), 30G (0.30mm), and the largest is 29G (0.33mm). Insulin pen needle features do not end with just the length and gauge. Different brands (manufacturers) offer different features. At Discreet Diabetes Supplies we sell a wide variety of the most popular brands of insulin pen needles, and we try to make your shopping experience and selection as easy and convenient as possible while having some of the cheapest and highly discounted prices.