$31.84See at Amazon.com
Compatible with 105mm F2.8 Ex DG OS HSM Macro lens. Hood adapter extends the length of the lens hood and provides more effective shading when used with digital cameras with an APS-C size image sensor. When using the APS-C Hood Adapter HA1030-01 with digital cameras with larger than APS-C size image sensor, vignetting will occur. Please remove the hood adapter if you are using these cameras.