Exclusively for Prime members, Amazon offers the Mangroomer Professional Do-It-Yourself Electric Back Hair Shaver for $15.23 with free shipping. That's $8 under our March mention and the best deal we've seen. (It's the lowest price today by $14.) It features a 1.5"-width blade, fully extendable and adjustable handle, handle lock, rubberized grip, and rechargeable battery.

Note: It may take an extra one to two days to ship.