STOP RENTING SINGLE HORNS!!!  This is Briz's newest model and it is amazing.  Where else can you get a horn with perfect compression, amazing build quality, and a sound that FAR surpasses anything else on the market at this price.
The model 105 is lacquered with a detachable bell and comes with a backpack/flight case - thus your student can carry it with ease to school.  It has a smaller handgrip so that younger players can hold it comfortably.
Briz has done it again with this horn.  Currently rentals cost about 60/month, in about a year you'll have paid the same to rent a crappy horn, when you could have simply purchased this one, AND you can re-sell it to recoup most of your investment when they move up to one of those fabulous Briz double horns.