When I'm mobile throughout the day - I recommend a roomy pump bag. I have the Sarah Wells Abby and I find it perfect for a Spectra S1 + cooler bag + everything I bring. It has 2 side pockets, one for your pump and one for your cooler bag. There is space on top for your pump parts and even a laptop sleeve.

Couple of options:

• 1 set of flanges for each pump session you plan on. Put "used" flanges in a wet dry bag after the pump session. OR if you want just 1 set of flanges, use the Medela quick clean wipes to wipe down flange after pump session.
• Pump directly into your bottles. I have the Medela 4 bottle storage cooler and pump directly into Medela storage bottles (using an wide neck flange to narrow neck bottle adapter). So first pump, I pump directly into the bottles and then store in cooler. Then pump into 2nd set of bottles for 2nd pump. For the 3rd pump, I consolidate the bottles to free up 2 more bottles and pump into those.
  • Alternative - pump directly into storage bags, just store these in your cooler bag throughout the day.

Products I use when I'm "on the go":

• Sarah Wells Abby bag (there are more affordable options, I went with this one because of it's size and look. I work in a very "professional" setting and needed something that looked the part)
• Medela 4-bottle cooler & ice pack
• Wide neck to Narrow neck adapter
• Pump directly to storage bag
• Medela Quick Clean Wipes
• Wet Dry bags