Muay Thai gloves will differ according to the individual. Traditionally, some beginners will start with boxing gloves, but if you take your sport seriously you should eventually move on to a special pair of gloves.
With Muay Thai gloves, the wrist area tends to be sturdier and longer than you would find on a traditional pair muay thai of boxing gloves. The gloves are usually offered in one size fits all, but they vary on the weights of the gloves.
Some fighters will have different pairs of gloves for practice and matches. The gloves that you choose should offer good support for your wrists and should be used in conjunction with hand wraps to keep the wrist in place to avoid injury.
Also, make sure that the Muay Thai gloves are made of durable leather and not too synthetic of a material. Depending on how much you uses your gloves, for they should last you about three years but you may find that your gloves to wear out to faster if you uses them frequently.
A brand that I would personally recommend for a muay thai gloves is Hayabusa. They are constructed of premium leather, and an advanced padding complex, their gloves feature an ergonomic curvature and Hayabusa's Dual Cross Directional closure. Engineered for intense pad and bag work. Performance padding for maximum hand protection. Secure fit and feel prevents shifting and maximizes wrist support.