Based on the search results, there is limited information about the specific details of MJ Nails products, including ingredients or materials. However, we can provide the following information:

Positive aspects of MJ Nails services:

• Offers a wide range of services, including spa pedicures, lash services, waxing, nail design, and more.
• Provides a luxury spa experience with beautiful interior design.
• Offers reasonable prices and a 10-day guarantee for any nail service.

Negative aspects of nail products in general:

• Some commercial nail products contain harmful substances such as toluenesulfonamide-formaldehyde resin and methacrylates, which can lead to adverse effects.
• Certain nail products can cause allergic contact dermatitis, nail brittleness and thinning, and other negative effects.

In general, it is important to be aware of the ingredients in nail products and to choose products that are safe and non-toxic. However, we cannot provide specific information about the ingredients or materials used in MJ Nails products based on the search results.