Review on 🔝 BV Bike Commuter Carrier Trunk Bag: Velcro Pump Attachment, Small Water Bottle Pocket & Shoulder Strap - Top-Rated for Efficient Cycling by Doug Hawkins

The bag is light weight and attaches well to my seatpost trunk. Three Velcro straps (one in front is held near the center of the seatpost, the middle and rear wrap sideways around the trunk). With all three straps fastened, the bag stands still without swaying or swaying. The bottle holder on the back is tight and works perfectly. I didn't take it out in the rain and I didn't need a waterproof bag. The detachable shoulder strap is a big plus. I simply detach the bag from the rack after locking the bike by undoing the three Velcro straps. The shoulder strap can then be easily and securely attached. When you come back from lunch it takes a little while to reattach the bag with three Velcro straps, but the fact that it can be removed makes it worth the time and avoids security issues. Zippers definitely wear out with normal use - annoying but not a deal breaker.