The pen has about 4 doses in it so you twist it to set your dose. You attach a needle tip to the pen and give yourself a poke, press an inject button on the top and a spring loaded ratchet system pumps in the dose amount you set (making a wonderful ticking noise as it progresses). Pull out and toss the needle and put it back in the fridge for next week.
I do manual injection which involves doing the full prep work. It takes about 3x as long to setup but is still only about a 3-5 minute process in total.
