I recommend the Hukam ceramic gua sha.

This is the gua sha I use; its exact name is the Hucam Hand Therapy Gua Sha. As you can tell from its shape, it resembles a human hand, allowing for a much more delicate massage compared to other products. I purchased and used it based on recommendations from others, and I found that simply sweeping the textured side over my entire scalp morning and evening—much like combing my hair—masses my tense, stiff scalp, helping to relieve headaches and reduce tension. Also, since it is made of ceramic, I feel less burdened about washing it with water.