This Starlight Xpress Extension Tube has a T-thread. Designed for 26mm applications. OPT Product Number: SX-T-26MM-ETCustomer Note: This product is imported. Due to its nature, currency exchange and shipping rates may vary without notice. An updated total will be provided to you at the time of your order. *Starlight Xpress extension tube mounted on optional products and shown in photo is for illustratory purposes and may vary in actual size and appearance.