Product feature 1. Rack & pinion design, stable functioning. 2. Double cylinder structure, the double force could be achieved. 3. Guide hole is designed on the both side of the cylinder body, which is simple to install. 4. Standard come with both bumper & air cushion, providing excellent cushion performance. Note: HRS10/15 only has bumpers (do not have air cushion). Specification Specification 10 15 20 30 40 Cushion Type Rubber Bumper Rubber Bumper Bumper & air cushion Bumper & air cushion Bumper & air cushion Port Size M5 X 0.8 M5 X 0.8 1/8'' [NOTE 1] 1/8'' [NOTE 1] 1/8'' [NOTE 1] [NOTE 1] PT thread, G thread & NPT thread are available. Rotating angle available are 90deg & 180deg. Symbol read more