This 3D printed part is made from TPU and is very durable. It is made to protect your battery in a crash so the TPU takes the majority of the hit instead of the lipo. Also, it is very useful to use when flying in a parking garage over concrete. This can greatly help reduce road rash to your battery. Fits almost all 1300mah & 1500mah size batteries. Dimension of the protectors are listed here:
36mm wide x 74mm long

Balance lead holder fits 4S-6S