i am a month into this, so don't mind me if i say something here that everyone already knows or sounds lame. i started mixing my own juces (such fun!) and read how drops will be different sizes from different dispensers but need to be uniform for best results. sooo... i tried to stick an 18 gauge syringe into one of my various dropper bottles but though the syringe tip went in the very top, it hit a blockage and stopped short. upon closer inspection i noticed that up inside them, they all had a kind of t-shaped bit of plastic just under the tip. i took some small pointed nail scissors and clipped out the t-shaped portion, and out came that plastic bit along with a tiny tube-shaped piece, which cleared the end of the dropper. i shoved the 18 gauge into the tip of the dropper and... presto, it went in tight and securely. after modifying everything i have with a bottle dropper on it, i can now stick my 18 gauge all the way in to a dropper bottle, tip the whole bottle of liquid upside down, pull back on the syringe to get an exact amount, no mess, no waste, drops are all uniform, and no more squeeze/drip.drip.drip, squeeze/drip.drip.drip.... rinse syringe, stick in the next liquid bott, and i can mix new juice really quickly, whether in mls or drops. and all the dropper bottles still work to dispense drops just as well as they did before, no effect.