Our Toy Elf has created hay mangers with NO glues, No screws, NO nails. Just safe wood, and safe rope. These are just the most small-animal friendly mangers in existence!
Small: works for mini-lops, mini-Rexes, and other rabbits under about 6 pounds. Guinea pigs are hay monsters so really should go with larger size. 7" wide x 11 7/8" long
Large: works great for guinea pigs and buns over 6 lbs. 11" wide x 14" long
Remember: you want your animal to EAT a nice compact pile of hay about the same size as their body EVERY DAY.
P.S.: these mangers work very well over a litter box.