Weight: Approximately 24g (actual measurement) Applicable diameter: φ28mm-40mm * Actual circumference: maximum 140mm, please allow about 10mm of extra space. This is a mount for cycle computers that clamps onto handlebars, etc. It can also be attached to aero handlebars that cannot be clamped. It can accommodate Garmin cycle computers and cycle computers/headlights compatible with Garmin mounts. You can tighten and loosen it by turning the knurled knob. Shipped via anonymous delivery. If you purchase it together with other items that can be shipped together, we will discount the shipping cost.