Microlet Coloured Lancets Microlet Coloured Lancets are for use with all Microlet Lancing Devices & also fit most other conventional lancing devices on the market. They are silicone-coated to reduce the puncture force & provide a gentler way to draw a blood sample. Microlet Coloured Lancets contain seven different colours to helping remind you to change your lancet after each test. Microlet Coloured Lancets are 0.5mm / 28 gauge.