On the gas lift component itself there should be a small cap on the top, before assembling it, please remove the cap and this will ensure it functions correctly.

Delivered to your doorstep. Overall Dimension: 59.5 x 60.0 x 104.0cm. Fashionable and generous design; 360 degree swivel; Strong 5 castor; Comfortable and perfectly designed for people who work at desk for a long period; Easy to clean; Overall Dimension: W59.5 x D60 x H(94-104) cm; Seat Dimension: W48 x D47 x H(40-50) cm; Pad Material: Faux Leather + Sponge; Colour: Black; Supporting Weight: 150kg; Item Label: 5550-3478BK;