Dimensions: 190mm L x x 66mm W x 23mm D (not including endcap or lip)
Capacity: 50 rounds
Material: High Impact Polymer
Compatibility: ICS, JG, SoftAir, Tokyo Marui, and all other TM compatible SIG Series AEG Rifles
Mid-cap magazine offers stealth operation (without bb wobbling sound when you move) and "debatable" better feeding as the feeding design is closer to how a real fire-arm is loaded. As 470 round capacity magazines don't exist in real life, a good amount of mil-sim players prefer mid-cap magazine for a different type of gaming experience.
Due to the nature design of all mid-cap magazines, they actually function better once you "break them in". To do so, spray some light silicon oil into the magazine, load and unload it a few times until feeding is smooth. (To ensure the spring runs smoothly inside the reservoir.)