M-Wave Helios 5.3 rear With this LED/rear light from M-Wave you are always clearly visible in the dark. The lamp has three modes: constant and two flashing modes. The rear light is lightweight and is easy to mount to the seat post using the silicone clamp. Specifications: Color: black Material: plastic Dimensions: 6.5 x 4 x 3 cm (L x W x D) Clamp diameter: 22.2 to 31.8 cm Weight: 35 grams Contents: 1 Rear light 2 AAA batteries