... Orange Silica Gel: Size: 1-3mm, 3-5mm, 4-6mm, etc. Package: carton drum, plastic bags, Tyvek bag > ... free,3 Its color varies as humidity changes.Use:Mainly for drying and indicating humidity of precision instruments, medicine, ... design and put into production.4.Quotation are offered for your unique sizes and some your special requirements.5 ... or to white (1-3mm, 2-5mm, 4-6mm, etc) for power transformers