perfectly embedded with no extra space. Suitable for most bicycles seat. Two adapters to match different sizes of seat rails, even if all adapters do not match, we also suggest finding a similar gasket in your accessories to install it. (Note: Airtag not included). bike tracker anti-theft hidden works perfectly. You don't have to worry about signal strength issues. protect your bike airtag even when riding on rainy days. Colour:black Material:plastic Package Contents: 2 x Bike Hidden Mount kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.