There are a wide range of accessories available for rabbits including water bottles and bowls, food bowls, hay racks, tunnels and toys, harnesses, carriers...
Your rabbit should always have access to clean, fresh water. For rabbits kept in hutches and cages, a water bottle attached to the side of the cage is the best way to provide this. Choose a bottle with a ball valve to prevent it dripping and change the water every day. Give the bottle a scrub at least once a week to prevent bacteria forming. During the winter months the water may freeze; you could either wrap it in some old material or buy a specially designed "bottle snuggle".
For house rabbits (no cage) the best option is a water bowl but avoid using these in cages and hutches as they are likely to become contaminated with dirty bedding. Choose a heavy ceramic bowl that the rabbit can't easily tip over (sometimes cat or dog bowls are better) and change the water once a day. Most rabbits prefer drinking from a bowl as it is more natural for them.
It is better to choose a heavy bowl that the rabbit can't tip over and you might like to have one bowl for dry food and one for fresh food. Scrub the bowls out at least once a week.
This prevents hay becoming soiled, which the rabbit is then less inclined to eat. It can be attached to the wire of the cage or hutch.
There are many tunnels and "hide-aways" on the market and these are great for giving your rabbit a safe place to sleep and providing stimulation. The natural fibre ones are best i.e. those made of willow wood or compressed hay as your rabbit can also nibble on them which is good for its health and helps to prevent boredom.
Seagrass mats are safe for rabbits to nibble on and are very useful for covering areas of carpet that your rabbit might otherwise tend to nibble.
For example, sticks, balls or chew toys. These can be made of wood, material, plastic or metal. Again, the natural fibre ones are best and avoid painted toys or those treated with dyes.
There are two main types of harness available - those with straps and those that are like a jacket. They should fit closely but with room to get two fingers in between the straps and the rabbit's body. Never use just a collar on a rabbit; this can break their neck. Harnesses can be stressful for a rabbit and it takes time to train them to it.
A standard cat carrier works very well for rabbits as it is made of plastic and therefore doesn't matter if the rabbit pees in it. If you have two, make sure it is big enough to fit both of them in so you can take them to the vets together. Cardboard boxes with airholes or cardboard carriers from charities such as PDSA are also available but the strength of the box will be reduced if the rabbit gets it wet. Line the carrier with a blanket, towel or newspaper and hay to prevent the rabbit sliding around.