What is the difference between the Smart Roller, the Smart Flow Roller, and the Paint-N-Roll?

A) The SMART Roller has a ratchet power trigger that directly feeds paint to the roller cover, eliminating the need for messy paint trays for refills. The SMART Flow Roller has the convenience of being operated in two ways: battery operated or by a plunger release mechanism which allows for manual painting, filing and cleaning.

B) The Paint-N-Roll has paint supplied to the roller with a push of the plunger.