At just under an ounce you won't find a lighter belay device. The Bugette is perfect for glacier travel and other just-in-case applications. For heavy and/or frequent use you'll want something with a bit more metal to dissipate heat more efficiently and resist abrasion, but for emergency and occasional use the Bugette is the bomb.
This little fella has nice touches such as smooth edges and a covered keeper cable, and it's designed to work with ropes from 7.5mm to 9.5mm. In practice it's a smooth operator, working just fine for any normal belaying or rappelling scenario, and you'll barely know it's there until you need it.