We’ve had the best feeding results with these feeders. Easily refill with minimal disturbance to bees. A plastic top feeder with a screen to minimize drowning. Inserts into a shallow super (sold separately). We recommend to caulk around the screen to ensure there are no holes for bees to escape into resevoir. 10 frame holds 3-4 gallons & 8 frame holds 2-3 gallons of sugar water.