Looking for a lite, compact and cheap'ish day pack

Going to Alaska this fall for a 7 day hike in Lake Clark National Park. My main pack is an Osprey Aether 85. Unfortunately it's the original model from 2006 so it doesn't have the built in convertible day pack. I plan to do most of my overnight hiking the first 3, maybe 4 days. After that i'll be staying at one spot at night and doing day hikes out from there.

So i'd like to find a daypack that when not being used takes up minimal space and weight. I suspect my day hike items might include:first aid kit, water bottle, bear spray, GPS, binoculars, a snack or two. I don't want something super lite like a drawstring pack, but would like something with something somewhat decent for shoulder straps.

So lite gear experts, what do you suggest?

https://www.amazon.com/dp/B0092ECRNS/ref=sspa_mw_detail_5?psc=1

I guess there are various options out there, but I like my REI Flash 22 and 18. Not as light as BZH's suggestion (which looks good) but the Flashes have waist and sternum straps, which I find essential for a comfortable and stable load dayhiking, particularly scrambling

I like the looks of this!
Do you own one? Just looking for feedback on it's durability, zipper function, etc.

I can't help but to see something like that and think "Hmm... 33L capacity. I wonder how hard it would be add a hip belt and a frame and load lifters...". And, my brain dives into all the little details of how I would do it. I can't help it y'all; the making bug is like a disease.

Gossamer Gear Murmer

yes I do own one! It has a lightweight fabric, but have been very happy with the durability. Zippers seem pretty good. I haven't had any issues with them snagging or failing. I probably has more compartments then you typically need for something this small, but I really like it.

I ordered up the larger size and it should be here tomorrow!