This will not fit a Nikon D300 as stated in the description.
This fits your .
Make sure this fitsby entering your model number. Includes 2 x Transcend 64GB High Speed Class 10 SD (45 MB/s, 300x) Memory Cards for a total of 128GB MEMORY, The High-speed Memory cards are designed to store and process Photos and Videos at High Speed Rate with no lag time between pictures. Transcend 64GB High Speed Class 10 SD (45 MB/s, 300x) Memory Card is fully compatible with All DSLR Cameras including Nikon D7200, D7100, D7000, D750, D5500, D5300, D5200, D5100, D3400, D3300, D3200, D3100, D810, D810A, D800, D800E, D610, D600, D5000, D300S, D700, D300, D90, D60 DSLR Cameras. Includes an additional Memory Card Wallet Holder with separate compartments for conveniently storing each Memory Card separately, making it convenient to individually identify and protect each Memory Card from common damage such as scratch and water. Includes a Flexible Mini Table Tripod designed to assist capturing Photos and Videos in unique angles by customly bending and twisting it’s flexible legs + 2 Screen Protectors to avoid unwanted finger marks on a Camera screen. Includes a HeroFiber Ultra gentle cleaning cloth designed for cleaning electronics and accessories.