
Back in the old days we strapped a spare tubular tire under the seat with a tire strap. Now that we're back to using clinchers, this pack takes up even less space and looks great. Very light too. Perfect for road, I'm not sure about off road if you need more than a tube and co2 bottle
This Silca Mattone seat bag is great, no regrets for upgrading from my last bag. It looks really nice, very compact, and stays quiet/hassle free. I use it for a tube, CO2, tire lever, allen key, patch, and toss the ID/money in. It just holds the essentials, don't expect a backpack sized compartment.
I also have the Mattone Grande which I prefer for general rides because it holds 2 butyl tubes (I'm cautious). The regular Mattone is for faster group rides when I want to more minimal. I like the Boa. Pack is snug under the saddle. Zipper works well so far although haven't put it through too much work. Fabric is nice and appears to be waterproof and easy to clean.
My wife lost her last repair kit when the velcro finally wore out and it fell off. The BOA works great and can be tightened so that there's no shaking/rattling. It's just big enough for the basics; tire repair, tire irons, and CO2 bottle inflator.
I put this on my wife's bike with tubeless tires. It carries the tubeless plug, a CO2 inflator, tire irons and a tube (if all else fails). I have a Crank Brothers multi-tool that I strap on the outside using the BOA closure. I got this because my wife lost her last bag when the velcro attachment had worn out and the bag fell off.